Small generator for home use.

[Anteaus]

The main issue with solar is that in Dec/Jan the energy collected is only about a tenth of the summer rating. This doesn't worry people who are just fitting panels for the sake of the subsidy, since it averages out over the year, but to you the low output at the time of year a powercut is most likely would be an issue. Typically a square metre sized panel gives about 150W in really bright sunlight, but only a tenth of that under full cloud cover. In the UK, that will amount to about 0.3 kWh of energy per day averaged over the year, allowing for typical weather patterns (or the equivalent of two hours of strong sun per day) It's that winter minimum that's the issue to watch, though.

 

[ericmark]

There are special inverters made which can isolate, charge batteries, and even grid tie to increase power available. Using the special inverters the change over can be automatic but most inverters are not built this way.

So step one is do you want automatic back-up or manual? The one plug and two sockets is the easy way for manual change over. You have a mains supplied socket and a generator supplied socket and all essential power is from a consumer unit fed with a plug. On power failure you unplug from mains socket and plug into generator socket so impossible for both to be connected together.

Noise is the next thing inverters don't really make much noise but a diesel generator can be really noisy but cheap to run. Petrol generators make less noise and petrol inverter generators the noise varies with load so light load they tick over and rev up as load is applied.

With one job we had a special UPS which used a bank of batteries and two mains supplies however the UPS broke down more than the power supply so it actually made things worse not better. First house we had regular power cuts so second house we were careful to have some non electric dependent heating however we don't seem to get power cuts in this house.

48 volt inverters seem to work well however 12 volt inverters have such a heavy current they seem to fail all too often. When we considered UPS at one place I worked we found one for each computer was cheaper than one big one.

VRLA batteries claim to last around 8 years but in practice they seem to fail after about 4 years. A generator only deteriorates when used so a stand by generator could last 50 years.

Items with refrigeration need to be allowed to equalise pressure before restarting so the unplug and wait 5 minutes before plugging into generator supply is good. But lights you may want immediate so you may need a combination of inverter and generator.

<Moderator's note>
Some foolish squabbling posts have been removed and the thread locked