Many people in the UK have had solar panels installed in the last 8 years or so but very few know how to most use the electricity generated most effectively. This is understandable as most installations were presented to the customer as ‘fit and forget’. This isn’t total rubbish as solar will work ok when its just fitted and left to do its thing. However, even a bog standard domestic application can be used to cut energy bills dramatically.
The big concept you need to get your head around is getting solar export down to zero. That’s the goal…we probably won’t get there but we’ve got to aim high, right? Or low in this case. Anyway, we want to be exporting as little as possible because this means that we’ve used it onsite and therefore haven’t imported expensive electricity from the grid.
As solar electricity is very rarely stored (you will know if you have a battery-it will have been installed quite recently and will have been pretty expensive!), we need to match supply and demand. i.e. when you are generating lots of electricity get everything turned on, when its raining and you’re generating next to nothing, turn it all off. There’s obviously a problem here though-how do you know?
The answer is an easily read monitoring devise. There are a number out there and generally you get what you pay for. However, I believe that the best is the Eco-Eye SMART PV Energy monitor. Not too pricey at £79.95 but what it does which I really like is give you a traffic light system of:
red: you’re importing more than you’re generating. Turn off the tumble dryer!
amber: you’re pretty much at parity (give or take a watt or two). As you were.
green: you’re generating more than you’re importing. Turn something on quick!
Obviously this does require a bit of work initially but you’ll soon get into the pattern of peak times and you can know when things should be turned on or off.
I know what you’re thinking…what if I’m not in the house all day everyday poised to press buttons at a moment’s notice? More on that next time…