Update 2: You can't manage what you don't measure...
Updated: Nov 11, 2019
I’ll start with a confession, we didn’t know the energy our home consumed ! Whilst there can be no excuses, there are a few mitigating factors !
The way we buy energy in the UK masks our actual consumption: we have fixed monthly payments and when the electricity company put the prices up, we switched to the next company. We were paying 11.9 pence/kWh, which didn’t seem bad until our supplier went bust ! What we didn’t know was that we had consumed 14,800 kWh a year and we were about to get a big catch up bill ! …We now know that all this switching malarkey is part of the problem and hiding a desperate truth, the real cost of electrical energy is rising at 7% a year and we are not in control.
So what should we be consuming ?... first, a little background: it's a 1970s brick built four bed detached house, with the heating/hot water coming from a 2006 ground source heat pump, so we only use electricity. The Ofgem site suggests that we should be consuming around 15,600 (for gas and electricity), so we appear not to be doing too badly and at 74 kWh/sqm p.a. ok-ish. However our “grand design” future proof extension project is about to increase this to 25,750 kWh; then throw in a couple of electric cars that are in the pipeline and we are up to 34,600 !! And in need of three phase supply !!
Our consumption was going to more than double and our cost of electricity was going to spiral to over GBP 8,000 a year by 2030 ! Time to get to work !
Right, let's start by scrutinizing what we use today: we metered up what we thought the likely consumption suspects were. The GSHP uses between 50-60% of our power and whilst understandable, we noticed that every Sunday in the wee small hours, the consumption sky rocketed ! Well this is down to weekly pasteurization process using the hidden 4kW immersion heater !...did we need to do this every week ? and did the temperature need to reach 100 C ?...err No !
Next on the list were the underfloor electric heaters in the bathrooms, did we need them ? No - and so another 1000 kWh of savings were found, then there was my daily rounds to switch the lights off ! Overall, when compared with the same 5 month period last year we are already making a 14% saving. It's what we call in NSC “Measure and Manage” - finding those invisible energy “bandits” - and it's already on course to save us GBP 250 a year ! We now need to find another 32,000 kWh savings if we are to go off the grid, can we do it ? …At times I feel like the guy in HG Wells “War of the Worlds” who dreamed of underground cities and had made a start digging a hole in his back garden !