Eco-heating system for heat pumps

Ultimate Eco-heating system

Ultimate Eco-heating system

Ecological heating (Eco-heating)

The Eco-heating goal is simple.  To use free or green energy (solar/wood) so effectively that expensive fossil fuels, energy bills and the carbon footprint disappear.  The only reason to be attached to the grid is to supply it; well not quite, we might need the grid to smooth any fluctuations but we certainly don’t need much of it.

Modern houses are well insulated and need a lot less energy to run than before and a few technological advances have made Eco-heating absolutely viable.

As a starting point, a tank of water – a heat store – is required to integrate various heat sources and demands. A single heat store makes an excellent heating system but two tanks are altogether much better, especially when it comes to integrating solar and a heat pump. So much more is easily optimised with twin tanks that this is the future for eco- heating systems.

Before you start to plan your own ultimate heating system there are a few points to consider:-

Photovoltaic panels (PV) rarely produce their rated output.

On a bad day they produce only around a third of their rated output – say 50W per square metre.

Background electrical demand (fridge, computers, lights, TV etc.) can often be as high as 1kW

The PV panel array will have to be much bigger than the usual 4kWp (16 panels) for there to be enough surplus power to make an eco-house.

 A heat pump takes electrical power and delivers around 3 times as much more energy in the form of hot water. This engineering miracle might be the core of the system, but …

The power multiplier

The power multiplier

…. the times 3 trick (coefficient of performance or COP) is highly variable, and depending on outside temperatures and delivery temperatures, can vary from 2 to 5. The manufacturer’s quoted COP is for very specific conditions which you might not see very often.  Even the quoted power output of a heat pump will not be reached when it is very cold outside.


Air source heat pumps are a better choice than ground source heat pumps

They cost less and are easier to install. For the full argument see:-

PV + heat pump = Free heating

A heat pump on a COP of 3 redresses the shortcomings of the PV panels on that bad day, so a PV panel and heat pump combination can deliver 150W per square metre of panel and two or three times as much on good days.  This energy, in the form of hot water, can be delivered to underfloor heating which usually uses about 50W per square metre of floor and never more than 100W (which would make your feet hot).  So, for a rule of thumb, the PV panel area should be about half the heated floor area, plus up to another 20 square metres to cover background consumption.  Therefore, most self-supporting Eco-houses are likely to have up to 40 PV panels on the roof; a lot.

Air source heat pumps run much more efficiently during the day when the air is warmer.

Not only more efficiently but combined with PV panels much of the daytime energy produced is free.  Obviously big PV and a slightly oversized heat pump can produce excess energy which could keep the heating on after the sun goes down. The surplus energy will need to be stored in tanks of water – big ones.

A house with high thermal mass will also work better in this respect.

Solar thermal panels are much cheaper and much more efficient than PV.

OK, they don’t make electricity nor do they print money like PV can.  However, given some sun, they do produce very hot and free high grade water heating, so the system should have an excess of them.  Massive solar is hard to manage and here again big tanks are part of the answer.

Solar thermal panels can be made to run more efficiently.

Solar panels can only heat a tank that is cooler than they are. In winter when the tank is usually already hot and solar is weak the panels often stop working altogether.  Given 2 tanks however – one hot and one cool – the panels will run almost daily throughout the year and this dramatically improves effective panel efficiency. The Original Twist solar stripper circuit decides which tank, or both together, can use the available heat more favourably.

A pair of 500 litre tanks are only 2m high and together under 1.5m wide.  Tanks up to 500 litres can be made of light gauge steel so they are relatively cheap and easy to handle.

Gas boilers – not quite redundant

On the coldest night the heat pump with reduced power output and the lowest COP might be struggling, especially if it was sized within the limitations of single phase electricity. A gas boiler is a towering powerhouse by comparison, producing instant high grade heat at a low price. Hot water recovery times are just minutes and a shower could run hot forever if required.  For a larger eco-house, a gas boiler for very occasional use makes sense and ensures that there are no compromises to comfort whatsoever.

Under floor heating is not always best.

Bedrooms need to be heated quickly, often briefly, and preferably not with a hot floor under the bed.  Floors of upstairs bedrooms are often reasonably warm already because they are above rooms which are heated all day so paying to heat them more makes little sense.  The answer for bedrooms is the fan-coil unit which is essentially a hot water powered fan heater. Not only will they heat the room in minutes, but connected to a suitable heat pump they will cool it as well.  Air quality can be enhanced by UV purification, a boon to asthma and hay fever sufferers.

Towel rails are different.

After your shower the towel rails will need to be on long after you have got up or gone to bed. The timing and heating requirements for towel rails is completely at odds with the rest of the system and they need to be properly integrated with a dedicated supply.

Wood burning stove

Mankind has been sitting round fires for thousands of years; for many people it is unthinkable not to have a real fire in the home.  We are talking eco-heating here so an open fire is out of the question but a good stove is much nicer to live with anyway.  A big stove with a big view of the flames will be too hot for most rooms so it will need to be connected to the water tanks in order to take some heat away. That’s no bad thing as high grade hot water is not so readily produced by the heat pump. A well matched stove can usually cope with all the hot water and heating needs which relegates the heat pump to an auxiliary role and certainly means that smaller heat pumps can be considered.


Although it is not an absolute requirement, the eco-heating system will work much better with a home automation system such as the Z-Wave Vera. The hot water circulation system, for example, can be activated by sensors in the bathrooms when they turn on the lights. Temperature sensors and relays to activate pumps and valves can be found in the Qubino Z-Wave flush relay which has a built in temperature sensor.  The destratification routine (see below) can be triggered by the integrated temperature sensor and the short pump runs monitored by a controller which easily copes with ‘if this then that’ situations.

Efficiency – the humbug

Just a reminder; the sun is free. There is no need to agonise over panel efficiency. The most reliable flat plate thermal panels are cheap so if you need more power just add more. Anyway, during the hotter months they are more efficient than evacuated tube types.

To store daytime heat pump production, the target temperature needs to be raised and that is relatively inefficient compared with driving the under-floor heating directly. Again the pump is usually running free, courtesy of the sun, so the efficiency doesn’t matter.


The Eco-heating system

Considering all of the above your ultimate Eco-heating system should be like this:-

Much of the suitable roof surfaces will be covered in PV and thermal solar panels.

An air source heat pump

Air conditioning via the heat pump

Under floor heating on the ground level

Fan-coils in bedrooms

Fan-coils in some living rooms for air conditioning

A gas boiler (optional)

A twin tank heat store system. Up to 500 litres x2.

A wood burning stove connected to the tanks

A system that can optimally integrate all of the above with no compromises at all is a tall order.  Here it is though; the Original Twist Eco-heating System.

Two tanks it is then – one hot one cooler – but with some sound thinking around the connections to the heat sources:-

Domestic hot water delivery.       

Fresh and pressurised water is heated by the hot tank via a plate heat exchanger – standard heat store practice. However, as the hot tank water will be rather modestly heated by a heat pump, the ability of the plate heat exchanger to cope with icy fresh water can be compromised. So to warm the incoming water it first runs through an internal coil in the cooler tank before getting to the external heat exchanger on the hot tank. The pre-warming is not mission critical so there are no controls or pumps to worry about. It’s just a passive coil in the cooler tank.

Back on the hot tank the usual temperature limiting valve – anti scalding – has been dropped in favour of electronic regulation of the heat exchanger flow pump with a Steca  TF A603 MC+ controller. This slows down the pump to give a precise output temperature and so leaves more water at the top of the tank ready for more showers. The flow out of the heat exchanger and to the bottom of the tank is also cooler which aids cooling of the solar coil.

Water circulation around the house is essential to save water wastage and eliminate that annoying wait for hot water.  The same Steca controller also regulates the circulation pump speed.

Preheating the domestic hot water via the cool tank not only makes a heat pump a feasible hot water maker but it also raises the efficiency in a subtle way. The water in the cool tank is heated just enough to supply the floors and fan-coil units and a heat pump does that very efficiently. Blending this cheaper energy into the hot tank system gives an efficiency boost and also allows the hot tank to be maintained a little cooler which gives another efficiency boost.

Other potential heat inputs to the hot tank (wood, solar and gas) are not disruptive to stratification so hot water drawn from the top is always ready for service.

The solar stripper circuit.

Solar thermal panels connected to a hot tank which is already hot – as it would be with a stove or heat pump keeping it ready for hot water delivery – will be effectively switched off in weak sunlight.  But given access to a cool tank they will leap into action at the first glimmer of sunshine, practically every day of the year. Low temperature solar flow addresses the coil in the cool tank first but as soon as it is hot enough it is switched to the hot tank. The flow emerging from the hot tank is usually still very hot so the return flow to the panels goes back via the coil in the cool tank to strip out some more energy.  The panels not only run throughout the year but more efficiently due to a cooler return feed.

The Original Twist Solar Stripper Circuit achieves all this with a special 3 port Coster valve that does not interrupt flow as it changes over. The solar pump is started by the cold tank sensor and everything is managed by the Steca TR 603 solar controller which also modulates the pump speed to keep flow temperatures up.

With two solar coils in use, a bigger solar array can be used without resorting to the absurd remedy of using an external plate heat exchanger and circulation pump. Absurd? Imagine sunrise, the panels and the pump start up, the tank is destratified and your morning shower is there no longer. Dooh!


Heat management

With high grade heat sources connected – a wood burning stove and solar – the hot tank can get very hot. High grade heat is a valuable commodity so the system hangs on to it as long as possible but excess energy will have to be moved eventually. The system does this in 4 stages, each triggered by a cascade of temperature levels.

Destratification  – First the pump for the hot water plate heat exchanger is activated for short bursts. This moves hot water down the tank and effectively increases its capacity.  The process is limited to the maximum return temperature a wood burning stove can tolerate before the back boiler starts to kettle.

Blending the tanks – If surplus energy is still arriving, a valve connecting the hot and cool tanks opens and the cool tank starts to warm up via a thermosiphon. In this way a wood burning stove would provide for masses of hot water first and then go on to address the central heating. The valve sets to open in a power cut and is controlled by the overheat stat for the hot tank.

Overheat thermostat 2 – In the unlikely event of the cool tank reaching 70 degrees, the overheat thermostat starts the heating pump to dump heat to the heating system or a purpose heat-dump fan-coil.

Power free heat dump – As a last resort, and in the case of a power cut, a power free valve in the hot tank is activated to flow cold mains water through a small coil and send energy down the drain.  It is hard to envisage a system where this would really be required but the option is there.

Heat pump integration

The floors pump and the fan-coils pump first draw water from the tank, the repository for free energy. The heat pump runs when the tank temperature becomes too low and then the flow goes directly to the floors or fan-coils. The latter can only be achieved if the heat pump circulation pump flows slightly more than the demand pumps and there are a couple of ways to ensure that. When the heat pump is running under PV energy during the day it will top up the tanks or supply heating depending on demand. Heat pump set points to suit fan-coils or floors will be triggered by the relevant circulation pumps and by the PV output.


You might imagine that a sophisticated control system would be needed but that is far from the case as many of the functions are independent of each other with only temperature levels causing any interaction.  For example, the circulation pumps for floors and fan-coils are only activated by programmable thermostats and the latter do not call the heating.  The heat pump is timed and only tops up the tanks if temperatures fall enough to call it, otherwise the wood and solar do the job. Destratification and blending are all independently triggered by temperature levels.

Simplicity is a major benefit. Should any problems arise there is no need to call in a specialist expert.

Who makes it?

In the first instance I will help you to specify and match the various elements of the system so that a bespoke specification is readied for production by the British manufacturer.

The system is based on a standard heat store with a few additions and those additions contain nothing new or untested.

Despite the simplicity this is the absolute cutting edge of Eco-heating systems.

Pre-wired and plumbed this is a quick and cost effective way to solve all your heating issues. The successful integration of wood and solar means a smaller and less expensive heat pump can be used with fewer P.V. panels to drive it. Considering all these savings and minimal running costs the Original Twist Eco-heating System is what every new Eco-house needs.

To see if this, or a single heat store, would be suitable for you just use the contact form and we can discuss your requirements.


The Original Twist Eco-heating system

Features summary

Stainless steel tanks – should last a lifetime

Total of 1,000 litres for energy storage

One cool tank for virtual stratification.

Mains water pressure is maintained but tanks are unpressurised

No hot water is stored – legionnaire’s avoidance

2 stage hot water heating for heat pump compatibility

130Kw heat exchanger for hot water making – more if required

Hot water circulation

Anti scalding

Suitable for solar input of up to 14kW

Solar stripper circuit for dramatically enhanced panel efficiency

Special large ports for wood burning stove gravity connection

Extra sensor pockets for home automation compatibility

DHW prioritised with energy overspill to heating

Condensing gas boiler optimised – controlled return flow temperature

Heat pump optimised and compatible with other heat sources

Heat pump efficiency raised through extra daytime running

3kW immersion for backup heating

4 stage safety system for energy control

A mix of under-floor heating, towel rails and fan-coils can be used

Fan-coils and a suitable heat pump can give air conditioning

Electric and hydrogen car charger

H2 charger

H2 charger

Above is the modern version.  Opposing garage doors on the side allow ‘drive through’ on the full turntable version.

The height required by the PV panels gives room for a live/work space above. No need to drink a lot to make the room go round!


Below is the 2014 concept sketch

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The Original Twist rotary solar tracking P.V. garage was proposed a couple of years ago and already needs an update to keep up with our twist on the future.  The hydrogen future.

Photovoltaic arrays perform some 20% better if they track the sun so the 24 panels on this rotary sun tracking garage perform as well as 28 static ones. 4 extra panels would cost £1,000 so tracking is worthwhile and of course adds to the FITs return. In addition to tracking the sun, the front and rear sections also tip up or down to get the most of morning and evening sunlight. The front set can tip up out of the way whenever the sliding garage door is open; alternatively they rotate out of the way to a preset parking angle.
A conventional array would have problems with the varying inputs across the panels but here each panel has its own micro-inverter which also enhances reliability and the performance reporting via wi-fi is fabulous.
The 300W panels together make a 7.2kWp array which is pretty punchy for domestic purposes and would leave a good surplus after charging the car inside.  Power can be allocated for domestic use or for generating hydrogen via a simple electrolosis idea we all saw in the school science lab.  A gadget like the Immersun 2 makes sure that these demands are prioretised so that the demand of choice gets the first bite of the free power and other choices only run on surplus power. In this way all hydrogen production could be guaranteed to be free.

To get into the vibe lets have a look at a day in the life of the Original Twist rotary garage.  The car inside is a plug in E.V. with a hydrogen fuel cell range extender. It can autonomously park itself in the garage and automatically connect up to recharge the batteries and top up the hydrogen tank.  The garage rotates to track the sun, of course, but it also turns the car round ready to collect you from your front door all heated and fueled up.  A simple car that fuels itself automatically completely free of charge is certainly compelling. What future for smelly old petrol?

Everything we have talked about is available right now so this is only made futuristic by the novel assembly of concepts.  It’s certainly not too early to consider building your next garage on a turntable.

While you could start off with a regular plug-in car the hydrogen versions will follow shortly. Check out the web site for a good example.

Eco Heating News

Heating News  Jan 2016

An Eco-house restoration case study

New Controller from Z-Wave and a chip upgrade

Clearview stove price check

Ultra cheap LED bulbs

£4 automated kettle

Eco restoration case study

We were constructing our dream house for a family of four. A total roof off renovation and extension of a 140 square metres, stone-walled Italian farmhouse in the hills near Città di Castello.  Heating is a big issue in Italy and having rented a farmhouse for a number of years we knew first-hand how brutal the winters can be!  This is how we met that challenge.

Judging by the freezing house we rented and friends’ houses, we knew we had to avoid the miserable conditions they suffered along with huge heating bills.  Insulation was an essential first step and with the help of architect Marco Carlini we built a ventilated roof that was almost over the top in efficiency terms, but then there is no such thing as too much insulation.  Plenty of insulation under the floors ensure that the heating is pretty responsive – by making sure it goes up into the tiles and not down into a freezing cold concrete slab underneath (yes, heat travels in all directions!)

Heating with gas was never an option, a pellet stove offered expensive fuel with noise and maintenance. What we needed was to burn wood (the cheapest source of energy) and add free solar power to that; how to integrate all these things workably and efficiently was not at all clear but fortunately eco-heating consultant Patrick Littlehales stepped in with a total solution which was clearly going to tick all the boxes.  After a whole day in a heating seminar all the clouds lifted and the final system was not only obvious but remarkably simple too.  Basically it’s a big tank of water (Specflue 500L heat bank) a Clearview 750 stove with back boiler and an extra big set of solar panels. Probably the one thing that brings this off is matching the overlap of the power curves as winter heat (wood) gives way to summer solar – when the curves overlap you don’t need another source like gas to fill in.

Patrick is a great exponent of ZERO COST heating and we loved that idea. It was simple enough; photovoltaic solar panels on our new roof would make enough money to pay for wood and minimal electricity.  To catch a good tariff Marco Tufi from IWT Engineering put the panels on the old roof and then they were later transferred to the new roof a year later when it was ready.

Going into our second winter the system has met all our expectations – we just love it.  The 14kW stove is a focal point and is a joy to operate. It easily heats the house (radiators/UHF upstairs and UHF downstairs) and provides masses of hot water. The tank has a 3kW immersion heater and I fitted an additional 2kW one to use some of our free electricity.  The oversized solarthermal array has been startlingly successful.  Three panels from Sunerg sit on the bank by the house (fantastic bargain – thank you Patrick). They are angled steeply to catch the winter sun and tame the fierce summer sun; the resulting flat and wide power curve gives remarkable performance in the shoulder months, even into January.

Living in the countryside brings the risk of being stranded in the snow and power cuts – a potentially deadly combination.  Our stove and tank are simply connected with no pumps so we can cook on the top (we do anyway) and keep warm come what may.  Not many homes have that level of security. There’s no risk of our heat bank overheating since it thermosiphons perfectly to two upstairs radiators – slowly dumping the heat – an additional, power-free way of heating!

Was it hugely expensive?  Yes and no.  The up-front equipment costs were certainly weighty but offset by the ease and speed with which the heat bank and all its pumps etc. was installed. In this respect it was practically free.  The fact is that the investment will be paid back relatively quickly (Photovoltaic the longest in around 7 years) and after that we’ll live almost cost free in our dream house – what’s not to like?


A new controller from Mi Casa Verde as Z-Wave gathers pace.

Mi Casa Verde have just released their Vera Plus smart home controller for a mere £140.  For anyone considering starting a home security system, with the option of a host of home automation features thrown in, this is really good news.

Vera Plus lets you easily set up, monitor and control lights, cameras, thermostats, door locks, sensors, alarms, smoke detectors, lawn sprinklers and more from practically any brand. VeraPlus supports 1400+ devices from all major brands and works with many popular devices using Wi-Fi, Z-Wave, ZigBee, or Bluetooth.  All this is unified under one single app which runs on any tablet or smart phone.  You can buy Vera Plus from and get plenty of advice at the same time.

Z-Wave itself is moving on with the release of a third generation of the chip found in every device. This gives better range between devices which in turn extend the range further in a meshed network.  Extended range means that security sensors can be placed further out from your house to mark out your first perimeter.  I love the idea of having a table lamp give a subtle flash when guests are arriving – it’s not all about the burglars.

Multiple functionality is emphasised in the new chip so now if you buy a motion sensor it is likely to measure temperature and light levels too; all useful features when controlling lights or heating.  Another example is the Fibaro flood sensor which includes a tilt sensor (so you know if someone moved it), temperature sensor, a siren, a light, a built in Z-wave network range tester.  If you leave your house unattended for long periods, you might feel happier if you had popped one of these on the floor.

There are now 250 firms making Z-Wave products, so you might start off with a controller and a couple of sensors, just to get the hang of it, but after that adding more features is a never ending journey.

Clearview 750 prices.

I’ve had a couple of enquiries recently so here is the latest quote from the factory for the ever popular 750 flat top with the 7kW back boiler.  N.B. When I’m supplying tanks and stoves I always try to round down the prices and they come with loads of free advice too.

Stove              £1,782

Back boiler       £312

Colour               £60

UK delivery        £49

Total                  £2,203

You might ask why the Clearview is so popular when it is also rather expensive.  Well there’s robustness for a start. Folded up quarter inch plate is tough and indeed rather weighty; it takes 4 strong men to move one.  Then there’s the clip in – and easily replaceable –  stainless back boiler. A leaky, crack prone cast iron stove with integrated boiler might save a few bob now but you might have to buy a couple more during the lifetime service of a Clearview.  A cracked stove could ruin your floors and rugs and leave you without heat for weeks. A fate to be avoided at all costs. Personally I prefer the plain looks and the huge glass doors giving a great view of the fire.


LED light bulbs – cheaper than cheap!

Take a look at and check out a range of LED bulbs starting from £1.50!

Now that’s just as cheap as any other type of bulb so there is no reason to hang back.  And yes you should bin any other bulbs immediately in favour of LEDs which consume about a tenth as much as an incandescent bulb.  An old 60 Watt bulb running 2,000 hrs a year (if it lasts) will cost £26 to run in Italy and £14 in the UK so the cost of the bulbs is becoming trivial compared to the running costs.  I’ve just bought a shed load of bulbs from Trillion and they seem fine with the warm white ones (2,700K) a good colour.

£4 automated kettle

Do you make the early morning tea?  Don’t you hate standing around in the cold waiting for the kettle to boil?  £4 at Amazon for a square timer plug will change your life.  Last thing at night, fill up the kettle and leave it turned on. Set the timer to come on when you wake up and only get out of bed when you hear the kettle click off. Nice.

If you’d like to talk about heating, cheap pool pumping, solar panels, stoves, tanks and everything else please use the contact form here.

DIY heating system

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click to enlarge



Simply the best

Could it be that the very best high performance ecological heating system is also less expensive than a conventional system? Could it be so simple and quick to install that you could do it yourself?

Yes absolutely, is the answer to both questions if you use a Specflue Xcel heat bank which, in my opinion, is still the best available.

It is DIYable because all the pumps and wiring are already fitted to the tank so all the techie bits are done for you; one of my plumbers says he can fit one in a day.

Because it is an open vent system it is absolutely safe and anyone is allowed to install it.


I could go on forever about why it is the best high performance system but here are the main points:
Stainless steel tank will probably last a lifetime – I prefer the 500 litre one.
Solar panels and woodburning stoves are properly integrated.
Heat pump connections, if required, are sensible and prevent destratification.
Condensing gas boilers run in condensing mode all the time and deliver their full power.
Recovery times are almost instant due to stratification.
Domestic hot water is pure and plentiful enough to equal 4 combi boilers running at once.

You don’t even have to install it all at once.  Just keep adding the next bit when time and funds allow.

See here for a brochure

I have installed many systems like this. In the days when solar PV gave good returns some of them were ZERO COST for all energy and my own house still makes a profit of about £1,000 a year. The system has been refined over the years and now there is even a special factory version of the tank incorporating a few of my favourite tweaks. I am also very particular about the way it is installed and the thermal characteristics of the house are modeled to make sure transmission matches power etc. I am also very picky about wood burning stoves; you’d be amazed how many people buy the wrong one.

If you are interested in having a go then you can depend on me for lots of advice and supply of a matched set of the heat bank, stove and panels in the UK and across Europe. I try to round down on factory prices and, within reason, give free advice so there is no better way to do your project.

Just use the contact form below to get going and I look forward to discussing your project with you.

Electric sports car 2020

EV Chassis

EV Chassis

Chuck a car out of the back of a Hercules and gravity will accelerate it to 60mph in under 3 seconds. It is no coincidence that, back on the ground, a few supercars also accelerate this fast. They have enough power to give a push on the ground equal to their own weight; a similar scenario to the car falling out of the sky. Friction limitations of normal road tyres level the playing field for all these powerful cars but in the next 5 years there will be cheaper sports cars and hatchbacks that can perform better and they will be electric. Bosch have just announced that a game changing range of lighter and more powerful batteries are on the way. Significantly this year’s Pikes Peak race was won convincingly by an electric car powered by six Yasa electric motors. Four of the motors used in the racer will do fine for an example of how our future car should perform. Allocating one to each wheel of a 3,000lb car means that it has to transmit 750lbs of shove on the road to push 750lbs weight to match the supercars. With a reduction gear of 2.8 the Yasa 400 motor has enough torque to do this and yet still not run out of revs before 190mph. For brief periods the maximum combined power of the motors is 880bhp so that should be erm, adequate if twice the power of a Porsche Turbo can be called adequate. In practice the acceleration should be better than anything on the road today because with each wheel finely controlled to prevent wheelspin the grip will be as good as it gets.
Individual wheel control will also transform road holding and handling. Imagine cornering with the outside wheels getting extra power and revs to augment the steering; worries about oversteer and understeer will be things of the past. In the same way that your satnav spookily shows the road ahead the on board computer can calculate the best power allocation to all the wheels to enable a safe trajectory through the bends and at speeds not really experienced in any car yet.
As mad as all this sounds there is no obvious reason why it should be particularly expensive. The layout of the car seems fairly obvious. The backbone chassis carries the batteries as centrally as possible and an inboard motor for each wheel is attached to the chassis. As the drive shafts are strong enough to handle immense power it makes sense to have inboard brakes integrated with the motors and then it is just one more logical step to have the suspension mounting points integrated into the motors as well. These power and suspension units can be deployed over a wide range of vehicles so, as we said, there is nothing particularly expensive here, in fact, quite the reverse. Roll on 2020.

Modern house boat

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click to enlarge

Introducing the Original Twist canal going house boat; in the style of a narrow boat only bigger, better and absolutely modern. As a living unit it presents an economical lifestyle choice. For £160,000 you get very low cost housing and maybe some change left over for a holiday house, long ski breaks and other good things. A comparable land based house or flat would be twice the price because of the cost of land, a boat on the other hand effectively rents the river via the canal licence.

A house boat might be small but as well as reduced outgoings there are some great advantages. You are never stuck anywhere you don’t like; if you need a change you can just cruise to somewhere else, maybe near a cosy riverside pub. River life can be like an aquatic pub crawl but without the driving. You’ll make more friends among the friendly and hospitable canal community too, especially with the most interesting boat on the water.
There is more scope for travel than just the English waters as you can get a tow across the channel to use a huge French network extending all the way down to the South of France where winters are not so harsh. Otherwise the house boat is an attractive proposition for a house swap so the whole world is your lobster.
It’s a tough life being retired!

The Original Twist Eco-house boat is all about, modernity, comfort and enough economy to make a modest pension go far. Many traditional ideas have been updated to achieve this.

Unlike a go-anywhere narrow boat ours is 10 feet wide and 55 feet long – we’ll forgo visits to a few stretches of narrow canal in exchange for a lot more room and the garage – yes that’s right, a garage.
The shell of the boat is normal steel but without the enclosing steel roof parts. The front saloon and the rear transom are full height steel as is the central bulkhead that separates them. The two open parts between the steel constructions are connected at roof level by tubular trellised ladder frames which run the length of the boat interrupted only by the central bulkhead. The open parts of the boat are then covered by 2 insulated wooden rooms made of plywood and foam panels (SIPS).which are factory prefabricated – complete with windows, pipes, wires etc. This makes the boat lighter, cheaper and better insulated.

The two central living spaces house the kitchen a bedroom and shower room, all with heated floors. Each has a large pop-up roof (just like on a camper van) to give a more spacious feel while being flattened whenever a low bridge is encountered. These roofs carry the solar panels and can tilt sideways in either direction to catch the sun – the simple mechanism to switch hinge points is activated by the flick of a switch.
The steel and glass front saloon is very light and airy with a door giving access to the front deck. Standard fan-coil units are turned on end to make a pair of powerful demisters for the huge windscreen and to heat the room too.
A flat sun deck on the roof of the saloon makes a great place to watch the world go by and as we shall see later the boat can be steered from up there too.
The steel rear transom accommodates the propeller shaft, engine mounts, rudder mechanism, a niche for the air source heat pump.  A tail hoist mounted across the back (like on delivery trucks) supports a light vehicle such as a Polaris RAZR side by side.  After adjusting the height the ramps are dropped and locked onto a nearby bank so one can drive off in style and comfort. What is life without wheels?  Because the hoist can be folded up, the length of the whole boat can be shortened to navigate some of the tighter locks. An awning can be extended over the vehicle and there we have it; the first house boat with a garage.

The real point about eco-technomologicalness here is to get along as cheaply as possible without damaging the planet. The 24 solar panels on the top produce a nominal 6kWp; more than most domestic arrays and enough for the small air source heat pump and to charge the batteries for the electric hybrid drive system. The hybrid drive is almost identical to that on the Original Twist hybrid 3-wheeler found on this site; here with a Lynch motor and a Kohler water cooled diesel. The usual benefits of a hybrid drive are there; the batteries give a few hours silent cruising and the diesel can take over indefinitely. The batteries are mostly solar charged or sometimes diesel engine charged with the Lynch motor doubling as a generator. Many moorings supply electricity so the batteries can be charged on cloudy days. With the air source heat pump the heating will run cheaply and conveniently off connected electricity or the batteries.  So there are 4 sources of heating power; the PV panels, wet panels, outside electricity and engine cooling . Most boat engines are cooled by river water but here a second coil in the heat bank uses the 60% of wasted heat to make hot water. There is no connection to the river or the gunk that blocks up the filters (boat owners nod knowingly here).
Heating is state of the art with a couple of tweaks. Twin heat banks with my stripper circuit make year round use of the 3 wet solar panels and the tanks are plumbed to optimise the little 2kW heat pump which delivers about 6kW. N.B. River water is not used as the heat source. See ‘Air source heat pumps in Southern Europe’ also on this web site.
Notable omissions are a wood stove and any gas as there is no need for either.

Control of all the lights, heating, entertainment and even the steering is done by i-pad and Z-Wave meshed radio modules which are cheap, reliable and plentiful home automation items. Narrow boats are usually driven from the back, a bit like a bus driver standing on the rear bumper. We can sit at the front in the saloon and steer from there or from anywhere else within range of the wi-fi; perhaps the sun deck even from the nearby pub! The Z-Wave controller allows for plenty of home automation tweaks like lighting control, security and leak detection, all from anywhere in the world. Theoretically the boat can be driven from anywhere there is an internet connection.
Actuators to move things like the roof panels and the rudder are operated by compressed air which is cleaner and easier to maintain. An i-pad and Z-Wave relays makes child’s play of these things; even a simple dimmer switch allows proportional control of the rudder.  The motorised satellite dish also needs to fold into a recess in the centre section when a bridge is encountered.

Neat extras
To make the kitchen a great place for eating while admiring the view the picture window on one side tilts up and out and a table is pushed outwards to make use of the outside space. Once parked up an extending awning over a drop down side deck, complete with an extending Barbie unit, makes an outside cooking area.

Central dust extraction – The centre section houses a fixed dust extractor plumbed to outlets around the boat to make cleaning much easier.

With a boat like this life will certainly be rich and varied.

ECO-HIPPY – One who is sufficiently off-grid to live almost cost free.

Heating News – Autumn 2015

ENGLAND FRANCE ITALY – Transcontinental Edition

Heating consultancy – England, France, Italy
England and Italy are covered so if you need a stove and a heat bank just get in touch, wherever you are, and I’ll get them to you. My usual transport goes from England to Italy every 2 weeks via France so sensible heating is equally available there. Just fill in the contact form below and we can start to chat.

Heating – Not too late for this winter
A system makeover might seem like a daunting prospect but it can often be as simple as connecting a new tank in your technical room to a few pipes that are already there. The most essential connection is to the wood burning stove; all the other power sources like solar and gas can be added later. There is an immersion heater on the tank to provide backup power if it is ever needed.
A heat bank and stove can be shipped out in about 6 weeks and installed in as little as 2 days.
Not only will your heating bills reduce dramatically but you’ll be cosy and in most cases safe from power cuts. If you were snowed in for 2 weeks without power would your existing system give you heat and cooking facilities? System continuity in a power cut is one of the most important considerations when designing rural heating systems.
Make sure you are safe and comfortable this winter. There is a contact form below.
Special offer on Solar panels
If you buy a stove and tank together I’ll arrange solar panels at trade price – like a big 3 panel kit with pump, controls and fluid for €2,000 + IVA. This is top quality Italian kit at a spectacular price especially as it‘s in Euros.
If you are in the UK or France I’ll do a similar deal and get the panels sent out to you from Italy.
(Subject to supplier price change)

Italian farm house scores a ‘C’
We’ve had the Energy Performance Certificate done on our Italian farm house as it’s up for sale. All the eco systems fitted to the house were officially vindicated by an unusually high ‘C’ rating, narrowly missing a ‘B’, so this proves that old stone houses can be efficient. Apparently the energy rating is an important factor as far as house buyers are concerned and quite rightly so as the wrong systems can cost a fortune to run.
Briefly, the spec. that achieved this was:
Wood stove (Clearview 650) with back boiler
Specflue heat bank
Wet solar panels
PV solar panels
Underfloor heating
Insulated roof
Double glazing.

The whole energy package actually returns a profit every year but we were still relieved that the applied criteria gave a respectable result.

If you’d like to talk about a high performance heating system like this please get in touch using the contact form below. Many versions of the system have been fitted in Italy and several refinements have been added to make it a well honed product known to the supplier as ‘The Italian Job’.
UK energy costs
Gas Gas Gas! If you live in the UK and have access to town gas you have enviably cheap energy. About 3p/ in fact which means a big 28kW gas boiler costs about £1 an hour to run and 50p for the typical smaller boilers. Knowing that winter lasts for about 200 days gives you a guide to your potential gas bills; 4hrs a day = up to £800 down to £400.
The exact cost depends on the boiler efficiency of course and a condensing boiler will get around 93% (versus as bad as 75% for an old one) but – and here’s the rub – only if the temperature of the return water is low enough to enable the latent heat to be condensed out of the exhaust gases. Upping your efficiency to 93% will save about £280 a year so the boiler is a good idea but it will only return a good result with low return temperatures. The best way to guarantee this is to fit a new tank or, to be specific, a heat bank like the one from Specflue. This stainless steel tank has a long list of benefits, such as integrating solar, wood stoves, under-floor etc but with regard to gas use and hot water delivery it is particularly impressive.
The gas boiler is directly connected to the tank (i.e. no coil) and can deliver full power to hot water to give fantastic recovery times and also continuous use of multiple outlets rather like an overpowered combi-boiler. The return temperature is managed and always correct for condensing mode. Hot water is extracted via an external heat exchanger so the hot water is fresh and pressurised so you can fill the kettle and saucepans with hot water. The pressure you get from your hot taps will now be the same as your cold taps which will put a bit of zing into a previously dribbly shower.
Don’t be put off by last winter’s bad press on condensing boilers – ‘Thousands left without heat in cold snap’ etc. Plumbers were quick to blame the kit but it was the condensate drains freezing and this problem can be bypassed with a break in the tube; the water drips into a funnel and any overflow is caught by a small plastic bowl.

UK electricity.
I used uSwitch to get a deal for 12.251 p/ after an informative chat with one of their advisors. A £400 annual saving so well worth the cost of a phone call. He will also tell me when a better rate comes up for a free switch to another provider..
It was interesting to note that Economy 7 at 6.232p/ was still twice the price of gas so the immersion heater is pretty much redundant as is economy 7 itself in most cases. The exception would be an air source heat pump where, despite a poor night time COP due to low temperatures, one would still be running a little cheaper than gas. The all electric eco-house is a possibility then.
UK electricity is almost half the cost of Italian electricity. As a rule of thumb every 1kW for 8 hours a day will cost you £1 (£365 a year) and this could be near your current use as a power meter usually reveals background consumption of around 1kW with a few lights, fridge and computers.
Replacing a 60W bulb with a 10W LED saves 5p in just 8 hours (£18 a year) so chuck all those old bulbs in the bin NOW and remember those curly CFL bulbs are not comparable so go straight to LEDs.

Eco house design

click to enlarge

click to enlarge

I was thinking about a small but overtly modern eco-house design a while ago and realised that it could not be smaller than the panel area required to run the small air source heat pump on a winter day. So the design is basically a big set of panels with a small house underneath. A 6kW array would be good for just over 2kW, just enough to run a small ASHP which in turn would be able to heat the well insulated house. Here is a sketch of what the house could be like. Using modern building materials it would be unusually low priced for the amount of space provided.
See the full article here
Comments welcome.