how does this actually work ?

[Paul2129]

I seem to keep having a reoccurring interest in solar, and after a fairly failed attempt at working out if panels could be installed at my business, I'm moving to a house with a good sized south facing roof. Incidentally, the business installation would have been great, there's a huge amount of electricity usage there, but a split-up system, and a shaded flat roof as part of the install, with not-so-great annual production numbers meant that I gave up the idea in the end, shame since there would have been some nice tax advantages there.... and my electric car would be there during daylight hours, but....

      I realise that I don't actually understand how this systems work, at least how I would use the energy produced and when. I guess that the panels are ultimately connected to their own electricity meter, this clocks up whats produced ? would I also assume that your regular electrical connection to the grid remains the same, you draw the same actual electricity that you always did, whilst the solar works on a separate system, sending their power back to the grid ? is this total production Kw number which the solar produces put against what your regular meter used, and your bill calculated in that manner ? so if you used 100Kw in total, and your solar produced 50Kw of it, ultimately you'd pay for 50Kw ? (other than perhaps the solar generated electric is sold back at a lower price than what you have to buy it for ?)

so, you're never actually connected to your own solar production ? and it makes no odds wether you charge your electric car every night or during the day, just that your panels produced enough to charge your car over that complete year in total ?

I'm tied with frustration of not being able to achieve the nice feeling that I'm helping the environment and 'doing my bit', with the annoyance that the system couldn't be installed at work, which would have advantages for tax, it's true that (I think) there are still some advantages in charging the car at work, not least because it'll always be topped-off when I arrive home, but also obviously the non-solar assisted power is still able to go through my accounts

frustrated, as always, splitting hairs, as always

any comments appreciated

 

[Murdoch]

The business case for solar has been undermined by the reduction in FIT rates ..........................

Spend your hard earned money on something else..

 

[Paul2129]

and yet the government really out to be encouraging us all to adopt renewable energy solutions, thats a shame

 

[binky]

ok, under the original FiT conditions, just generating electric was all you needed to do. YOu wwre getting paid more in FiT than the electric you buy, so you could just balance out the yearly bills. Ie of you spend £2k on energy but could generate £3k ib FiT then you would be £1k better off, plus any reduction of energy you didn't buy fron the grid.

I'll try to explain what happens. Your panels during daylight hours will be generating energy as DC electric. The inverter (which is the cleverest bit) converts DC to useable AC electric that passes through a meter (generation meter) before deing connected to your AC electrical system. The generation meter being used for the FiT payments. What the inverter does is monitor the AC electrical supply, so if the mains connection is at 240V it will ouput the converted electric from the panels at a higher voltage such as 243V. Like water at  a higher level,  the electric from the panels will therefore 'flow' first. So say the panels are generating 2Kw and you are using 1.5kW, then you will use electric from the panels and 500w will go back to the grid. If the panels are generating 2kW and you are using 3kW, then you will use all the energy from the panels topped up by 1kW from the grid. Now given that electric is about 15p per kWh and the FiT is currently about 3.5p then there is much greater emphasis on saving 15p's than generating 3.5p's for the fun of it. Given this state of affairs it may be worth installing a solar car-port at your carpet shop to charge the car up (it will also feed any spare into the shop). Like wise at home an array may be worth installing if you use a lot of electric during the daytime - washing clothes, hoovering, lots of gadgets constantly plugged in, or you have an electric jacuzzi or immersion on a hot water tank. Ideally you want to sink generated electric into savings off your household bills. HOt water is really good for this, customers tell me that they can heat pretty much all their water from spring to autumn from solar, saving gas or electric.