The Trouble with Heat Pumps Part 1

Domestic heat pumps are being heavily promoted by energy companies and the Green lobby as an efficient way to cut carbon emissions while simultaneously reducing  consumer energy bills. 

But do the figures really stack up? In fact is either of the above claim true? Or are the promoted advantages of heat pumps based more on wishful thinking than reality?

There is so much hype going on around Heat Pumps it is difficult to separate the facts from propaganda. But as this topic has been bugging me for some time I thought I would have a go and maybe puncture a few of the propaganda bubbles and economies-of-truth surrounding heat pumps. 

So here goes.

There are two main types of domestic heat pumps. Ground source heat pumps (GSHP) and air source heat pumps.  (ASHP). 

The first two posts will deal with GSHP’s then I’ll cover ASHP’s and in a final post I’ll look at the often stated aim of nationally replacing domestic gas heating with heat pumps. I'll show what I think are some extremely serious financial and electrical issues society will have to deal with if a mass adoption of heat pumps were to be seriously attempted.

Ground Source Heat Pumps. (GSHP)

By any measure, for a normal family installing or updating  their domestic heating with a GSHP, it will be an enormously expensive operation. In addition to the basic installation costs there are also other significant costs that are, if not hidden, quite obfuscated.

The Energy Saving Trust estimated the cost of installing a GSHP in a typical family home at between £14,000 to £19,000. (HERE)

Selectra (HERE) give a slightly higher but more detailed cost break-down

Notice from the above Selectra chart, a bore-hole system (which intuitively feels like the less costly of the two techniques) actually involves over twice the ground work cost of a horizontal system.

So the cheapest GSHP system will involve installing an underground pipe network under your garden. This means your home has to fit the following criteria:  

    • You have a garden (which will be trashed and need relaying)

    • It is accessible for heavy machinery

    • It is on a sufficiently pliable bedrock/soil

    • Your garden is big enough.

With regard to garden size The Ground Source Heat Pump Association (HERE) claim the following:

“As a general guide, for a newly built 3-bedroomed house of around 120 m with a heat loss of around 6kW, two trenches of 30-40 metres in length would typically be required.”

Note “with a heat loss of 6KW”. I assume it equates to the output from the heat pump required to maintain a modern 3 bed house at around 20degC. 

That’s a tiny heating system! Maybe suitable for a new build conforming to all the latest building regulations regarding insulation but hardly likely to be adequate for existing housing stock.

I’d suggest the vast majority of the current UK housing stock would have a lot of difficulty maintaining warmth all year round with a mere 6KW and two forty meter trenches.

EverGreen Energy (HERE) suggest as a rule of thumb you need a garden size of:

"..roughly twice the total floor area of your home from every storey.

The Centre for Alternative Energy (CAT) (HERE) suggests you need 10m of “slinky coil” per KW and that a typical 8KW heat pump requires 400 sqm (20m x 20m). According to the CAT you need 5 meters between the trenches. 

I suspect that both the EverGreen estimate and the CAT estimate assume unrealistically thermally efficient housing. But never mind. We will run with it anyway.

So, how big are typical houses in the UK? Savilles (HERE) tell us what the average floor area per house type is. So using the “twice floor area of your house” rule of thumb we can get a rough idea how big a garden you need for installing a GSHP into each type of house.

Typical Detached House:

• Floor area 152 sqm. 
• GSHP area (twice house floor area) 304 sqm.
• Minimum required garden size: 18m x 18m or 57ft x 57ft

Typical semi-detached house:

• Floor area 93 sqm. 
• GSHP area (twice house floor area) 186 sqm.
• Minimum required garden size: 14m x 14m or 45ft x 45ft

Typical Terraced house:

• Floor area 83 sqm. 
• GSHP area (twice house floor area) 166 sqm.
• Minimum required garden size: 13m x 13m or 42ft x 42ft

What percentage of the UK homes have gardens that big? 

In  fact from (HERE) 1 in 8 UK homes have no garden at all! Of those who have a garden, the median garden size (i.e. the size where half are bigger and half are smaller) is 188 sqm. Which suggests that houses whose garden (if they have one and including front and back) would be big enough is about one third of the total number of UK homes.

Of those with big enough gardens most will be homes owned by the more well-off in society. Especially in London and the South. Notice the NONE of the above fulfil the CAT requirement of 400 sqm for an 8KW heat pump.

If you then assume that only one space (front or back garden) could be practically used for the piping, I would suspect you would eliminate all bar 10% of homes. Of those, almost all will be older and more expensive properties.

So what about bore holes? 

Look at the Selectra table (above) that gives ground work costs. Notice that vertical ground work costs are at least double (with most approaching three times) the cost for horizontal systems. So while there would be less stress on garden area when installing a vertical system, there would be considerably more stress on the bank account. 

Also notice that nasty little reality check paragraph underneath the Selectra table. It details some (not all) of the building work that is excluded from the price estimates.

Water temperature

GSHPs can only efficiently heat water to around 40 degC rather than the typical 65 -70 degC of a gas system.  In just about all domestic scenarios GSHPs are less capable than condensing gas boilers. 

As a result of the low output water temperature you need to install (recommended by most) underfloor heating with your GSHP. Alternatively you could significantly increase the size of all your radiators.

Either way you trash your house. 

To cap it off most companies selling these systems also highly recommend you upgrade your homes thermal insulation as well (assuming that is that there is anything left in the bank account to pay for it)

From installation issues alone I would suggest that GSHP’s are wholly inappropriate for most properties in the UK. There will be exceptions. But they will be exactly that: Exceptions. Not the rule.

Lets not forget, all I have covered at this stage is the impracticality for installing GSHPs in most UK properties. 

I haven’t covered the practicalities in actually running the things yet. (that's in the next post). 

There is also the potential impact on the electricity grid if the proposed scenario of GSHPs and ASHPs replacing gas boilers ever came to pass. ( last post in this series)

The next post (on the problems with the day-to-day running of GSHPs) is HERE

France and Germany: Electricity and Emissions

There is a question at the bottom of this post - maybe you have an answer.

The vast majority of French electricity is generated from from nuclear and hydro-electricity. There are only residual amounts of electricity generated from fossil fuels.

You can see live data on French electrical generation Here At GridWatch. Below is a snapshot taken today.

In the snap shot, along with coal at 0.01GW (0.02%) France is using gas to generate 0.68 GW (1.4%) and Oil 0.13GW (0.27%)

So in France electrical generation from fossil fuels account for less than 2% of production.

But how does this relate to emissions?

For simplicity I'll leave out the real nasties like Sulphur Dioxide and Nitrous Oxide and just deal with Carbon Dioxide. When we compare these figures with Germany (see below) the real nasties would be just about in the same in country to country proportion as the Carbon Dioxide.

From The EIA FAQs here (and a little bit of maths) we know that electricity generated from coal produces about one Tonne of Carbon Dioxide for every MWh of electricity.

Over the day, from burning coal to make electricity, France dumps 10 x 1 x 24 Tonnes of Carbon Dioxide into the atmosphere. Or 240 Tonnes

From gas (550Kg/MWh) they dump 670 x 0.550 x 24 or 8844 Tonnes.

Finally today oil (816Kg/MWh) will dump 130 x 0.816 x 24 or 2545 Tonnes.

In total today, from producing electricity from fossil fuels, France will dump 11629 Tonnes of Carbon Dioxide into the atmosphere. So say: 12000 Tonnes max.

Now let us look at Germany. To reduce emissions and do away with its nuclear fleet, Germany has invested hugely in a plethora of wind turbines and solar panels. But its generation is still dominated by coal, with no real prospect of any significant reduction.

The German daily generation data is presented as a graph and the live graph can be found Fraunhofer interactive chart here. A snapshot is below

First of all, notice that Germany is actually using the dirtiest fuel known to man as base load (thats lignite or brown coal). Also its remaining nuclear fleet still adds about 9 GW.

Useage of coal and lignite averages out over the day at around 31GW. Gas averages out at about 2GW.

Although Lignite is significantly more polluting than hard coal I'll treat it all as hard coal for simplicity. Although Oil use is significantly above that in France we'll ignore it as it gets buried in the rounding as the rest of Germany's fossils fuel numbers are so large.

31GW of coal generation will over the day, produce 31,000 x 1 x 24 or 744,000 MWh and will dump 744,000 Tonnes of Carbon Dioxide into the atmosphere. Gas produces 2000 x 0.55 x 24 = 26,400 Tonnes of Carbon Dioxide. So say 750,000 Tonnes of Carbon Dioxide in total.

So, today in the real world, Electrical generation in Germany will dump somewhere around (750000/12000) 62 times more Carbon Dioxide into the atmosphere than Nuclear France.

Of course, Germany 82.5M has a larger population than France (64.5M) So per capita the

emissions ratio is less, at about 50:1

But just think on that.

In Energiewende obsessed Germany, every time an electric kettle is boiled to make a cup of coffee, 50 times as much Carbon Dioxide is released as when a kettle is boiled in nuclear France.

So tell me, who has the more valid solution to the emissions problem?

Wind, Bluster and Carbon Reduction

The IPPC commissioned Garrard Hassan to do a report on how effective wind power is at reducing carbon emissions. For those who don't know, Garrard Hassan are a leading consultancy engaged in the wind turbine gold rush. Commissioning them was a bit like asking the Jesuits to give an even handed account of Catholicism. But never mind. Here I'm going to expand on their main claim that in 2011 Wind power reduced Carbon Dioxide  emissions by at least 5.5 Million tonnes. I'll leave their comedic denialist style claims regarding intermittency and reliability to another post.

Their arrogantly titled report "Beyond the Bluster" is HERE. This "peer reviewed" report (peer review panel of one) bases a great deal of its gravitas on another (quite good) report "Empirical estimates of emissions avoided from wind power generation" (good quality copy available HERE)   Garrard Hassan interpret the results from this report  and then grandly come to the conclusion that in 2011 at least 5.5 million tons of carbon dioxide was mitigated by wind. Of course they cannot but help to gild the lily by then going on to claim that this figure could potentially save over twice as much if all the wind power was directly offset by cycling coal plant (which, of course, in the UK  it hardly ever is, and is frankly, absurd) So I think we'll stick to the optimistic 5.5 million tons and put the gilding down to a little over enthusiasm.

5.5 million tons of Carbon Dioxide. Sounds impressive. Unfortunately sounding impressive is not quite the same thing as being impressive.

Ideally wind will have displaced carbon intensive power production i.e. Coal. But in the UK it is unlikely that coal is ever directly replaced.  Gas displaces coal and then cycling the CCGT plant accommodates the intermittent wind supply. But let us be nice, let's assume all of the 5.5 million tons can eventually be reflected down to a shut down of coal plant.

Now coal is almost pure Carbon. In fact 27% of carbon dioxide by weight is Carbon. So our 5.5 million tons carbon dioxide equates to a burn of 1.5 million tons coal.

Now, what size power plant does that correspond to?

Well, one ton of coal roughly corresponds to 2 MW/hr of generated electricity. (See here) So our 1.5 million tons of coal correspond to 3 million megawatt/hrs. There are 8760 hours in a year. So we can work out what size power station could provide this in a year. (3000000/8760)

So our idealistic  reduction in coal burn equates to a continuous output of 340MW.

Now assuming a good coal fired power station operates with a capacity factor between 70% and 85% the 340MW equates to a single power coal fired power station of around 400 - 450MW.

So in 2011 (a windy year) the entire wind turbine fleet, at a subsidy cost of over £800 million managed to reduce carbon emissions corresponding to a single small to medium sized coal fired power station.

That is of course, if you believe the wind industry. Remember, this 5.5 million tonnes is NOT my figure it comes from Garrard Hassan - doyens of the wind industry!

This also means that the cost of offsetting that 1.5 million tons of coal comes out at well over £500 per ton in subsidy to the wind energy cartel. Every ton of coal saved from burning by wind costs us an extra £500 in subsidy on top of the actual cost of the power generation.

By chance an old clapped out, 50 year old Magnox nuclear power station in Oldbury was retired in 2012. It had been producing carbon free power for nearly half a century. Its rating? 430MW.

So every year for the last 44 years, this single small first generation nuclear power station reduced carbon dioxide emissions by roughly the same amount as the entire wind turbine fleet managed in a windy 2011.

Don't figures like that just knock you out?

Wind and the Myth of Fossil Fuel Subsidies.

One of the latest little scams our wind turbines aficionado's are trying to pull is to justify their obscenely expensive and ineffective Wind Turbine generators (WTG's) by inventing fictional subsidies to fossil fuels and nuclear. The latest and greatest of these has the carpet baggers claiming that that the massive ROC subsidy received by wind is on par with or even less than that received by gas, oil and coal.

Of course, this is a load of tosh. Just as it is a load tosh that wind is cheaper than nuclear (See this Post).

Here is a fine example of this bufoonery at The Guardian - Here  (where does the Guardian get their reporters from?). You have to ask: Do Guardian journalists ever read the documents they supposedly quote from? Or do they just do as they are told? 

According to our Guardian scribbler, poor hard done-by wind (which at best produces 1% total energy supply) "only" got £700M subsidy in 2010. Whereas (shock horror probe) the demon spawn of Satan (aka fossil fuels) received a whopping £3.63 Billion. 

He supposedly derives this from an OECD document available Here. Pity the journalist didn't read it first. I have to ask if Guardian journalist are just naturally lazy or so dedicated to spewing out propaganda they willingly subvert the truth to aid their carpet bagging friends in the wind industry.

At the end of this document from the OECD are three tables that summarize the subsidies received by coal oil and gas (produced at the end of this post)

Each of these tables itemise the folowing:
A "Producer subsidy" i.e. the subsidy received by the energy producer.
A "Consumer" subsidy which relates to the reduced VAT rate charged on all electricity and heating (however generated) 
Finally, a subsidy for inherited liabilities. (£8.5M - coal only)

These are the producer subsidies:
Coal: Nil (Coal provides approx 14% total energy)
Gas: £233M (Gas provides approx 40% total energy)
Oil: £301M (Oil provides approx 38% total energy)

These subsidies though are acknowledged by the OECD as for specific purposes, not like the ROC which simply lines the pockets of the shysters running the WTG scam.

What this ridiculous article includes in to order to get to £3.63 Billion is the Consumer subsidy. This of course, applies to all energy providers including wind and relates to consumers NOT providers. Wind (whose energy is also subject  to the same consumer VAT reduction from 20% to 5%) still gets an another £700M. All for their measly 1% annual contribution to the UK energy mix.

I can only see this as a fundamentally dishonest and decietful misuse of data in order to promote a mistruth. The fact that this appears in a supposedly  upstanding newpaper is absolutely unforgivable.

 You can guarantee ther wind industry and their pals will try and pull this trick again.

Just remember, even if you consider the consumer VAT tax reduction a subsidy, then it is a subsidy to consumers. It is a subsidy to people who use the energy NOT the producers. The reduced VAT tax on energy makes no difference to the wholesale sell-out price for that energy whatever it is derived from. It relates to fossil, nuclear, wind, hydro,  and any other energy generation technique.

This non existent fossil fuel subsidy just comes down to another self promotional myth from the wind industry and their sycophants.

One day they may start telling the truth. Just don't hold your breath waiting.

(tables follow)

The End of the German Solar Dream

So far the Germans have invested approximately 130 billion Euros in household and industrial solar power. (Roughly the same as the recent Greek bail-out)   See Here

Over a year solar now provides around 3% of their electrical requirements. (See Wikipedia Here)

Of course this solar power is only effective during the daylight hours and then only when the sun is shining. During winter the output is usually as close to nil as makes no difference.

The headline solar installation capacity is (for 2011) 24.8 GW. If that was really the effective output it would amount to 30 medium/large Nuclear or fossil fuel power stations (assuming a typical capacity factor of 80%).

Sounds impressive.

Unfortunately the claim is deceptive, if not down right fraudulent.

This is a snippet from the above Wikipedia article

When you do the sums you find that the actual yearly solar output is just over 8% of the much heralded maximum.

The actual energy produced by these 130,000,000,000 Euros worth of solar averages over the year at less than two and a half Nuclear or CCGT or coal power stations power stations, each rated at 1GW with an 80% Capacity factor.

Even then, the solar output is of course intermittent. Not only due to the the obvious night time limitation of solar, but due to variable solar intensity due to time of year and the inevitable periods of cloud.

The net result of this is that the 130,000,000,000 Euros worth of solar does not displace anywhere near 2.5 GW of fossil or nuclear plant.

Let us be kind and throw caution to the wind.

Lets say that this 130,000,000,000 Euros worth of solar saves carbon emissions from 3 coal powered stations each rated at 1GW.

That averages out at over 43 billion euro per coal plant shut down. Hardly an economic or environmental miracle is it?

Let us do a comparison here.

A CCGT gas plant produces less than 40% of the carbon emmissions of a coal plant. So to save the same amount of carbon as this expensive solar plant (but in a reliable and on-demand way) all you need  to do is replace 5, 1GW coal plants with 5, 1GW CCGT plants.

A 1GW CCGT plant costs around 600 million Euros so you can do the same thing  (but also produce reliable dispatchable and on-demand electricity all the year round) for about 3 billion Euros. Or just over 2% of the cost of solar. The running costs of the gas  plant would also be considerably less than the feed in tarif payments of 10 billion paid annually for the solar plant.

Of course if the Germans coiuld get over their collective phobia regarding nuclear then you could save the same amount of carbon by replacing 2.5 Coal plants with 2.5 modern Nuclear plants

Even using the ludicrously inflated figures from the anti nuclear lobby the  cost would be only 7.5 Billion Euros or 5% of the solar cost (actually the real figure is about 3%)

Like the rest of Europe, Germany is sitting on an ocean of shale gas. Germany also has the technical expertise to exploit 3rd and 4th generation nuclear as well as cutting edge nuclear such as MSR or LFTR nuclear plant.

If they had avoided the quasi-religious dogma that forced them down this solar blind alley, they would today be reducing their carbon emissions. instead they are about to massively rise as they replace nuclear with coal.

Instead of a dynamic, low carbon and cutting edge power generation network, the Germans now have their self indulgent and next to useless solar money pit, plus their equally hopeless wind farms - all backed up by dirty coal.

No wonder some German politicians are running scared. ( See Here ) ( and Here )