A lot of people start with off grid systems, but whats best?
off grid or on grid aka grid tied?
Lets get this started right as people have very much a misinformed view of how this works or would not and what saves money.
Grid tied inverters will NOT work when the grid goes down.
Grid tied inverters only save you what you can use.
Grid tied is cheaper.
Grid tied can be limited.
Grid tied has ongoing fees.
Off grid gives you independence.
Off grid works, even without the grid
Off grid is robust and costs less than the grid tied equivalent.
Off grid is less limited.
Off grid is a one off cost.
Grid tied is parallel and off grid is not, this difference can make a difference when it comes to integration or you can just switch over.
Off grid starts usually with a shed, garage or workshop being taken from the grid, or it may not have had any power. it seems logical to "test out" solar and how it works with a "small project" but it often grows very quickly - you have been warned!
The benefit of a off grid is that they are grid forming ( makes the power) so if there is a power cut you still have your lights on. but you can be integrated into your home with transfer switches, if you know what your doing. For example your lights, you could run a cable to the lights and switch between off grid and on grid lights.
This is probably the easy option as a modern light circuit is low power, each energy bulb is around 6watts. You will probably use more power running the inverter over the actual load.
You may also want to run a set of sockets off solar with its own circuit, this is a little more work chasing (laying) cables and finding green sockets or something to distinguish the two power source. you would want to do this as you don't want to run a load of extension cables all over the place. trip hazards and messy.
One benefit is that you can have a larger inverter as you do not have to meet G98 or G99 regulations as its not parallel with the grid, so you can grab a 5kw inverter and run your power. I would suggest that you know about electricity before you start and make a plan.
you would want to have the output fused, you may want to them have a distribution unit, and then run a suitable cable to the home, where you will distribute the power as required and safely.
when it comes to grid down, its important to not cause a grid and off grid scenario as there is magic smoke and a smell that takes ages to go away. you would want to pull the tails ( the big cables) and place these in a transfer switch so you have the grid on one side and your off grid on the other. This also means planning for running the house and its power demands.
Going off grid for your power requirements totally is not going to be that fun with in the UK due to the feast and famine, but as we work with many off grid installations is not that hard or involved. you will need to have a generator. red diesel would be ideal, and you simply charge the battery with the generator and this can also supply the load. With charging required to various degrees over the year, you are looking at around 90 days where solar may not be the best. you would want to over size the battery if you are off grid so that you can get the most of the 80% faster charge area of the battery.
Solar should be set up accordingly as south roof mounts are not going to cut it. You will need to set up a winter array for sure, and spread the time of the peak. this would need a good area for solar panels to be set up and mounted. but in general from March you can come off grid or off generator in the UK until late October.
if your off grid the standing charge of grid power should cost the same or less to power the generator over the required time.