PV powered Central heating

[emerald]

hi guys,
i looked at a job yesterday, the customer currently has a coal fired boiler, pumped heating and grav hot water, he also has a large array of photovoltaic panals, he is normally over producing between 2 and 5 kw, and instead of selling bk to the grid for the fraction of what he is paying he has asked if i can some how store it, and pump it back into his central heating that evening.

indirect must be the best approach for this i guess?

im thinking either a large cyl, 2x immersions, high performance coil,
heat cyl to 90 and then pump heating through the coil,

or
a thermal store arrangement with external plate heat exchangers, and no mixing valve on,

what do you guys think,? will this even work and at best how long would say a 300ltr cyl last in a large house with 14 rads?.

cheers

Dan

 

[stevetheplumber]

hi guys,
i looked at a job yesterday, the customer currently has a coal fired boiler, pumped heating and grav hot water, he also has a large array of photovoltaic panals, he is normally over producing between 2 and 5 kw, and instead of selling bk to the grid for the fraction of what he is paying he has asked if i can some how store it, and pump it back into his central heating that evening.

indirect must be the best approach for this i guess?

im thinking either a large cyl, 2x immersions, high performance coil,
heat cyl to 90 and then pump heating through the coil,

or
a thermal store arrangement with external plate heat exchangers, and no mixing valve on,

what do you guys think,? will this even work and at best how long would say a 300ltr cyl last in a large house with 14 rads?.

cheers

Dan

cant imagine it would last very long atall maybe running storage heaters would be a better option

 

[jay s]

maybe air source heat pump could run off pv. customer must be green to have pv so might like idea could heat hw and heating although many consideration to take into account and am no expert in this field so going to shut up. just a thought.

 

[emerald]

The point is he wants to produce the heat during the day whilst it's free and use it later, don't think storage heaters are an option here, I have chat to him about ground source and air source, not intersted, he thinks I. can just put a cyl in and that would run his heating, think I'll have to tell him it won't work unless you guys have any other ideas

 

[stevetheplumber]

i think the problem here is water isnt a good medium for storing heat i seem to recall from the dim distant corner of my mind that stones have been used like this large amount of stones buried beneath a house which was heated and vents were opened to allow heat out basicly a great big storage heater probably somewhere like sweden using hydro electric as a free ish heat source

 

[emerald]

a few years ago, when i worked for a renewables company, i remember fitting a 3000 ltr store which was directly heated by a giant wood pellet bolier, this was then directly connected to the heating system and was pumped around as needed, just thought i could scale this down abit, i think it is asking abit much to be honest. think he would be happy to use up what is there and reheat as required, but the guy doesnt seem to understand that this is a costly way of trying to add to his heating,

it would be ok if we could demolish all his rooms and fit UFH ,

always want to help everyone out with what they want but i think ill give this one a miss, he has basically told me what he wants there, but if it doesnt work it im sure i will get the blame