Retrofit, for busy people
If I had to explain retrofit to someone in 2mins I’d whip out this diagram.
Starting bottom left, the ‘Existing’ bar shows the total building energy use split into three unequal portions. At the top is the electricity use from appliances and lighting. Below this is the hot water demand, then the space heating. The hot water and heating are produced (typically) by a gas boiler, hence they’re shaded a different colour. You’ll see the large proportion of energy assigned to heating, due to our UK homes being poorly insulated and leaky.
Moving right, a ‘Fabric First’ retrofit will increase the insulation levels and air tightness of the building. This has minimal impact on the electrical use or hot water (unless you bin all your appliances and stop showering - please don’t) but makes a huge impact on the heating demand as the energy you pump in, stays in. Using a Whole House Approach and independent professionals like Retrofit Coordinators will ensure the design and specification of these measures are effective and the risks are minimised.
A ‘deep retrofit’ of 60-70% reduction does two things: it neutralises the fuel price disparity between main gas and grid electricity (gas is 4x cheaper per unit) and opens up options for all-electric alternatives to a gas boiler: heat pumps, MVHR, electric boilers etc.
Your home is now insulated and airtight enough to benefit from a heat pump, so it presents an affordable and highly efficient way to remove all fossil fuels from your home. When your home is ‘heat pump ready’ you can choose when to switch across - hopefully with some government £££ incentives. You won’t need a huge heat pump because you’ve reduced the demand down already.
So, in the future, the national grid (which is becoming greener over time) will supply your heat pump which will convert every kWh of energy into 3kWh. This powers your heating and hot water. If you have the ability to utilise PVs and batteries, these can supplement your heat pump to reduce the pull on the grid and lower your bills. A solar diverted could squeeze a bit of excess free solar energy into your hot water tank. You may even fine tune your comfort levels with strategic electric infrared panels.
Right busy people, back to work! Remember 2050 - and Net Zero - is 315 months away.
If you found this useful, please share…and if you are able, take action.
PS. I produce these diagrams primarily for myself, summarising graphically what I have learned so I don’t forget it. This stuff is complicated but if you can capture a complex idea in a simple way then it is a great communication tool. Just don’t ignore there is complexity and nuance behind all these things.
