Domestic Solar - would it pay me ?

[Pasty]

Yeah, my last 40 tube system cost me about £3k i think, including the cylinder and pipework (DIY install), proabbly cheaper now but man alive £3k buys you a good bit of PV and it's more flexible....

True. Our thermal store is fitted with an immersion heater so it would be a simple hook up.

 

[f0ster]

If you are able to use most of the electric generated by pv you can install an export limiter to get around the dno refusal to allow more than 4kw.

 

[2YardOfLard]

True. Our thermal store is fitted with an immersion heater so it would be a simple hook up.

We have domestic solar. We costed "immersun" & "EMMA" etc that automatically divert power to immersion heater but we decided they were too dear for what they do. If you work at home you can just wait to flick the switch on the washing machine, turn the water on etc when the sun comes out. The automatic diverters only run certain very limited sorts of appliance such as immersion heaters & oil-filled radiators that take power in the same way. If you're around you can juggle which devices are on much more cheaply yourself (and it becomes a fun game! ) .

 

[Renaultman]

if you mean install it your self it is not possible. there are a shed load of qualifications required to be able to sign it off and get the tariff as well as being a member of a professional body, even tho the tariff is not the best at the moment the cost of an install has came down a lot also. you can install it your self if you are not bothered about the tariff and as long as you are using most of it you should do ok, the cost price of a 4kw kit is about £2500 ish

Sorry to hijack, or divert the thread.
Is there any point in using Solar and battery/generator back up to power fans/doors and low energy lights on a grain store. Mains electric runs right between 2 buildings but prohibitive connection costs have led me to just use a diesel generator to date.
Current demand is just roller shutter doors and 3x 13amp fans.

 

[Exfarmer]

I think you would certainly need to retain your generator to power the doors alone, in the event of bad weather and your battery being run down by the fans.
Solar alone cannot power most motors as the current flow is too variable, unless you have a very large install.
3x13 amp fans is a load of about 10kw to run these for any length of time will require a fairly large battery and or solar array. Yesterday a dull day a 50kw array I was working on was producing between 10 and 35Kw and a total of 183 KWh. However it has been regularly producing up to 250 KWh in the last month ,but down to 100 on others and even as low as near zero in some poor winter days.
Much depends on how long you wish to run the fans, from these figures a 10KW array would have given about 3.6 hours run time for the fans but would need a very substantial battery combined with it

 

[Renaultman]

I think you would certainly need to retain your generator to power the doors alone, in the event of bad weather and your battery being run down by the fans.
Solar alone cannot power most motors as the current flow is too variable, unless you have a very large install.
3x13 amp fans is a load of about 10kw to run these for any length of time will require a fairly large battery and or solar array. Yesterday a dull day a 50kw array I was working on was producing between 10 and 35Kw and a total of 183 KWh. However it has been regularly producing up to 250 KWh in the last month ,but down to 100 on others and even as low as near zero in some poor winter days.
Much depends on how long you wish to run the fans, from these figures a 10KW array would have given about 3.6 hours run time for the fans but would need a very substantial battery combined with it

 

[Renaultman]

I'm not looking at replacing the gennie. Just trying to take some of the load off,run the fans at harvest, charge battery tool batteries etc. Not sure whether to for a lightweight diy type set up with a couple of heavy duty 12v batteries and a decent inverter, or invest a bit more and try to run the fans etc

 

[Exfarmer]

I am not sure how you would work the three ( gennie, batteries and Solar). Conventional solar to mains inverters work, by pumping up the power to marginally above the mains to make the power feed out. Rather like pumping water into a system.
You would need something different in your case as they would each work against the other, if you were not lucky, until the voltage reached cut off point, ( 253 volts normally) then all would trip out in theory.
I may not be correct and you would need to speak to someone with more expertise.

A 10 KW array should provide something like 1000Kwh and 800KWh during the months of August and September. To give you an idea of the output during harvest season,

 

[f0ster]

You need an inverter that is programable. It needs to give priority to solar and when the battery voltage is down to a pre set level it starts the genny automatically, they are available I just cannot remember the make. the genny needs to be able to start up on auto from a closing contact on the inverter.the inverter is a victron. I have installed just such a system. He had no grid.