Home Cleantech is our way of describing the various ways that you can reduce your bills and carbon footprint by installing different ‘renewable’ solutions in, on or around your home.
What are renewable solutions anyway? They are various ways of producing renewable energy, which in turn can be defined as energy resources which are naturally replenished, such as sunlight, wind, tides and so on.
When we started researching for our own homes we found it was quite confusing, so we hope that these pages simplify the different types of solutions available as well as the “pro’s & con’s” of each.
Why The Existing Housing Stock Matters
As 40% of global emissions (& slightly more in the UK) come from buildings, a transformation in the existing housing stock is necessary to achieve the targets set to avoid global climate catastrophe (80% reduction from 1990 levels of carbon emissions by 2050).
Other areas where reductions need to be made, such as transport, are far harder to achieve in any meaningful way – can you imagine a world where only 20% of current aircraft travel levels are permitted? However, with domestic cleantech, the solutions are proven, cost-effective and pretty simple to achieve.
We hope the table below will help to explain the different domestic cleantech options available on the market:
| Heat | Electricity | |||||
|---|---|---|---|---|---|---|
| Heat or Electricity? | Heat (Hot Water) | Heat (Heating Water or Hot Air) | Heat (Heating Water or Hot Air) | Heat (Hot Water or Hot Air) | Electricity | Electricity |
| Capital Costs | £3k - £9k | £6k - £8k | £6k - £20k | £2k - £14k | £10k - £20k | £10k - £20k |
| Grants | Up to £400 | Up to £900 | Up to £1.2k | Up to £1.5k | Feed-In Tariffs | Feed-In Tariffs |
| Basic Requirements | 3m² to 8m² of roof oriented within 90° of South.Minimal shade. Room for slightly larger hot water cylinder | ≥4m² external wall space. House already insulated and draught-proofed. | Exterior space available for trench or borehole. Is the ground suitable? House already insulated and draught-proofed. | Fuel storage space. Flue (suitable for fuel). Smokeless Zone | At least 10m² roof oriented within 90° of South. Minimal shade. | ≥5m /second average wind speed. Planning permission. |
Fundamental 1: Central vs Domestic Energy Generation
Currently the vast majority of the energy we consume is generated centrally and then transported to our homes and offices via various types of ‘grid’ (electricity / gas etc). Additionally, most of this energy is generated in the first place from fossil fuels. Less commonly understood is the fact that central power generation is extremely inefficient, for example a coal fire power station loses 70% of the energy generated in the form of heat. Even the latest generation of Combined Cycle gas plants are only 55-60% efficient, meaning that 40-45% of the energy is lost.
The transportation of the energy itself is intrinsically inefficient as it requires effort and manpower to move or control it, quite apart from the fact that the energy itself depletes over distance (there is approximately 5% transmission loss in the UK).
Domestic Energy generation means that the energy you use to heat (or cool) & power your home is generated ‘in situ’ – it does not need to be moved anywhere apart from perhaps your roof or from the garden.
At It Won’t Cost The Earth we think that this is a key point in Domestic Cleantech’s favour. Whatever the other arguments made by vested interests or doubters, the fact is that it is more efficient to produce energy where it will be used.
Fundamental 2: Electricity vs Heat
Many of us get easily confused with what different forms of domestic Cleantech actually do. This is not surprising as the industry is not very good at explaining itself and replete with jargon! Let us help clarify it for you. Domestic Cleantech solutions generate energy in two forms, heat & electricity.
Heat: in the form of hot water or air, and used to either heat water for bathing / showering etc, or for central heating.
Electricity: to power household appliances and in some cases heating appliances (such as immersion heaters).
Electricity is higher ‘grade’ energy than heat. Put simply this means that it is more useful in that it is more flexible than heat (indeed it can be used to create heat via an electric fire or immersion heater for example). It is also higher grade energy than chemical energy (eg oil or petrol, for example).
The following table sets out what each Cleantech solution can and can’t do.
| Solar Thermal | Air Source Heat Pump | Ground Source Heat Pump | Biomass | Solar Photovoltaic (PV) | Wind Turbines | |
|---|---|---|---|---|---|---|
| Hot Water (baths, showers etc) | Yes | Yes | Yes | Yes | Inefficiently | Inefficiently |
| Central Heating (Water or Air) | Yes | Yes | Yes | Yes | Inefficiently | Inefficiently |
| Electricity | No | No | No | No | Yes | Yes |
† some systems claim to be able to provide both hot water and central heating but this is not common.
Fundamental 3: Value for Money
We are all concerned that whatever we decide to invest in, be it solar thermal, heat pumps or other solutions, that there is a clear financial return over & above the obvious environmental benefits.
It is quite easy to be distracted by the concept of ‘payback’, which is often used by critics of Cleantech to muddy the waters! In the ‘payback’ argument there is a misplaced focus on the period of time a Cleantech solution needs to be operating before it covers it’s costs of purchase & installation. Arguments rage over how long these periods really are which in essence are impossible to predict due to the volatility of fossil fuel energy prices amongst other factors (such as energy security, exchange rates and production costs of cleantech equipment). Besides, who measures a ‘payback’ period on a new kitchen or bathroom? And yet several new kitchens or bathrooms may be fitted to a house during the 25-30 year lifespan of a typical solar thermal system.
In our view, a better measurement is Return on Investment (“ROI”), which shows the percentage increase in the value of your investment. For example:
- You currently spend £300/yr on hot water for your home.
- You purchase and install a Solar Thermal System for £4,000.
- Your hot water spend reduces to £100/yr as 66% is being produced by the Solar Thermal installation.
- Your “ROI” is 5%, which compares favourably against the interest you would currently get on that original £4,000 if you had put it in the bank!
And what about the free hot water that you (or indeed the next person to live in the house) will enjoy until the system needs replacing (usually in 25 to 40 years)? The second part of this point is particularly important, as property values start to reflect purchaser’s desire for lower ongoing energy costs in the same way that broadband speed is already having an effect on house prices.
Finally, government pledges on the introduction of feed-in tariffs (“FITs”) from April 2010 and the subsequent renewable heat incentive (“RHI”) indicate that in some way the cost & value of any Cleantech solution installed will remain with the property. This will mean that the cost of installation will be spread across a longer period in much the same way as a mortgage is usually paid back over a 25 year period. Crucially, these incentives will also be backdated to 1st July 2009, so any installations from that date will be included.