By Paul Homewood

 

 

The Mail has a useful supplement about alternatives to gas heating, which is relevant following the government’s decision to ban gas boilers in new build houses from 2025:

 

Wonderfuel gas, crooned the 1980s British Gas advert. How times change. As we approach the 2020s, British households are now facing Government efforts to shift them off the ‘wonderfuel’ and on to something greener.

In a significant announcement on Wednesday, Chancellor Philip Hammond said he wants to stop the installation of gas boilers for water and central heating in new homes from 2025 to reduce greenhouse gases and carbon emissions.

Although Hammond said nothing about existing homes, he hinted at more proposals that could spell the beginning of the end for gas central heating.

 

Some councils, such as Islington in London, are already developing centralised systems where many properties are sent heat rather than gas via highly insulated pipes.

But most people will have to replace their existing boiler with a new ‘green’ design if they are to give up gas.

What is unclear is whether any of the alternatives – such as heat pumps and biomass stoves – can rival the claim made in the old advert that gas comes ‘at a price that can’t be beat’.

Although many eco-friendly fuels promise lower annual energy bills, the financial savings can vanish through the cost of installation and maintenance. And whilst there are incentives in terms of subsidies, perversely these are being reduced – just as the Government wants us all to do more to save the planet.

The Mail on Sunday assesses the alternatives you can turn to:

Option 1: DIG DEEP FOR THE HEAT

The earth outside your home may not seem warm, but it can replace your gas boiler as a source of energy to heat your home.

To harness the heat in the earth, you need a so-called ground source heat pump.

This means digging 4ft deep trenches and laying pipes containing fluid. The scale of the pipe network will depend on the size of your home and garden.

The fluid in the pipes is warmed by the underground soil, where temperatures are generally from 6 to 12 degrees Centigrade throughout the year – even when the air temperature is below zero.

 

Heat pumps: The scale of the pipe network will depend on the size of your home and garden

This fluid flows into a heat pump, which uses clever technology to heat water for the home. Crucially, the device squeezes the energy out of a very large amount of tepid liquid and uses it to heat up a much smaller amount of water.

It does this by a process called compression. Hot water is then fed to a tank and around the home’s pipes and radiators.

Installing a ground source heat pump involves major excavation work and is an expensive project, costing from £10,000 to £20,000. Homeowners may save £300 a year on heating bills.

There is also a renewable heat incentive grant worth on average £2,500 a year over the first seven years. The amount is calculated based on how much energy is produced. There is no guarantee the scheme will not be shut or scaled back.

Meredith Annex, of energy research company BloombergNEF, says a ground source heat pump is efficient but most homeowners would not be able to afford the installation.

She adds: ‘Such a pump also requires a lot of space so they are probably only suitable for people living in the countryside.

‘But people buying in a new development may benefit from the builder having installed it already.’

Option 2: DRAW ON THE AIR OUTSIDE

With air source heat pumps, any heat from the outside air is taken in through a special fan on the side of the house. It works like a fridge in reverse. While a fridge disperses heat from a system of pipes at the back to cool itself, an air source heat pump absorbs the heat from outside the home to warm it.

It is possible to get heat energy from the air even if temperatures are as low as minus 15C. Using similar techniques to a ground source heat pump, if enough of this energy can be harnessed, it can be used to heat water for the home.

Warmth from vast amounts of air is absorbed at low temperature into a fluid. This is passed through a compressor powered by electricity, and the resulting heat is transferred to the hot water system in the house.

The fan resembles an air conditioning unit – and takes a day to install. But you also require special radiators or underground heating pipes that can bring the total bill to about £8,000. It works best in well insulated homes. Homeowners should save £200 a year in heating bills.

You may also be eligible for a renewable heat incentive grant worth about £1,200 a year for the first seven years. Again, this is based on energy usage and should not be relied on as a failsafe way to get your cash back.

Use the Department for Business, Energy and Industrial Strategy’s online calculator to work out your possible grant. Go to www.gov.uk/renewable-heat-incentive-calculator.

https://www.dailymail.co.uk/money/bills/article-6817643/Can-really-scrap-gas-boiler-heat-home-soil-garden.html

 

The article also looks at water source heat pumps, solar panels and biomass boilers, but these have limited applications. As indeed does ground source heat pumps, which really need a lot of space, something not commonly found on new housing estates these days. GSHPs are also, of course, extremely expensive to install.

So, let’s look closely at air heat pumps, or ASHPs. The chart suggests energy cost savings of £200 a year, but it is not clear what this includes.

But Greenmatch, an online provider of green energy solutions, give some detailed costings here. They reckon the installation cost could be between £7000 and £11000. On top of this, more money would have to be spent on underfloor heating systems if the benefits were to be maximised.

However, when it comes to running costs, their numbers don’t stack up:

https://www.greenmatch.co.uk/blog/2014/08/the-running-costs-of-heat-pumps#running-cost-factors 

They say that the cost of running a conventional gas boiler would be £1005 a year. But this is nonsense.

Their own figures of 11000 + 4000 KWh, and 85% efficiency mean consumption of 17647 KWh. Gas is currently priced at about 2.5p /KWh, giving an annual cost of £441.

This tallies with my bills , as well as Greenmatch’s own chart:

 

 

They then list the running cost of the ASHP as £970 a year, more than double that of gas.

And this is before factoring in depreciation and interest on the installation cost.

 

As for the Mail’s claim of £200 savings annually, it may be that this is after counting the government subsidy via the Renewable Heat Incentive scheme (RHI). I have run the RHI calculator for our house, and the subsidy works out at £750 a year, payable for seven years.

It is certainly misleading for the Mail to claim that “heating bills are reduced by £200 a year”, if they have counted the subsidy.

 

In any event, there is no way the government can subsidise everybody’s new heat pumps, and the existing capped budget is close to being fully spent.

In practice, running costs for ASHPs are almost certainly going to be much higher than estimated by Greenmatch. As they point out, they are assuming houses are already well insulated. This is an important point.

A draughty house means that the heat pumps have to work much harder to maintain heating levels. This may sound obvious, but there is a definite amount of heat trapped under the ground or in the air, and the heat pump will have to work harder to extract heat if a great amount is needed, a fast supply is required or there is less heat than what is necessary.

In simple terms, you need to keep progressively putting in more energy to get out the same amount. [In technical terms, it has to do with the Coefficient of Performance (COP) which measures the efficiency of a heat pump and it does this by measuring the amount of power input compared to the amount of power output produced by the considered system. Hence, the higher the value, the more efficient the system is].

So either you have to pay more money out for proper insulation, or buy a bigger, more expensive heat pump, or accept that the system will struggle to supply the amount of heat you require.

 

The simple reality is that heat pumps, both ground and air source are not cheaper to run than a conventional gas boiler. On the contrary, without government subsidies they are considerably more expensive.

It is true that they are much cheaper to run than conventional electric heating systems, but that is another matter entirely.

via NOT A LOT OF PEOPLE KNOW THAT

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March 17, 2019 at 01:09PM