electricity costs - pv solar

G_M

I'm looking at a 3 bed semi. There's no mains gas, and retricted access so couldn't get oil delivered. Gas canisters are a pain, and expensive, it's heat pumps or all-electric.

What would be the (very rough!) supply/instalation costs of, say, 5 (day!) storage heaters plus pv solar panels to heat them?

And could pv panels actually produce enough power in winter for the heaters and ideally other power requirements?

PasturesNew

Don't forget a bit of wind power. They're not all hugely expensive and big towers.

Andy_WSM

G_M wrote: »

And could pv panels actually produce enough power in winter for the heaters and ideally other power requirements?

In a word...NO!

To give you an idea. In December last year, my 4kW PV system produced just 92kW. In June it produced 631kW.

The Sun is too low in the sky to be useful for heating during the Winter.

4kW of PV is 16 panels and is the maximum you can install without special permission from the Network Operator. Wind might be a better option for heating, but I'd imagine you'd need a pretty big turbine to charge storage heaters!

JC_Derby

Andy_WSM wrote: »

In a word...NO!

To give you an idea. In December last year, my 4kW PV system produced just 92kW. In June it produced 631kW.

The Sun is too low in the sky to be useful for heating during the Winter.

4kW of PV is 16 panels and is the maximum you can install without special permission from the Network Operator. Wind might be a better option for heating, but I'd imagine you'd need a pretty big turbine to charge storage heaters!

Actually it's 16a per phase. Which equates to about 3.68kw. I'd suggest in my experience most arrays tend to be about 4kw but are restricted by the inverter.
You should also remember that heat pumps are disturbing load, so again the DNO will need to be made aware. The newer versions tend to be invertor started.

matelodave

Even a heat pump with a solar panels isn't an ideal combination. You need heat when the sun doesn't shine or its dark so the consumption curve of a heatpump is completely opposite the generation curve of a solar array.
Here is a useful website with a couple of calculators that might help you determine what you might be able to achieve. http://solarelectricityhandbook.com/solar-angle-calculator.html

I've got an Air Source Heatpump and reckon I'd need at least 50 panels to generate enough power (about 9000kw during the year to balance my consumption. ie total energy generated = total energy expended. However it all gets generated in the summer and goes to the grid as it can't be stored economically. I then need to buy it all back at retail prices in the winter when I need to use it.

I doubt that a wind turbine would be of much help either as it would have to be fairly large and you would need to have a fairly high average windspeed to make it worthwhile.
We live out in the Fens with nothing in front and nothing behind and although it feels quite windy our average is a lot less than 5m/s so not really enough unless you can get a big one on a tall pole out in a field with very few trees or buildings near it. Waste of time in a town or city and it's unlikely you would get planning permission if it was.

Smiley_Dan

Well, you can "timeshift" that energy using a thermal store, but it all begins to get a bit complicated...

lstar337

The best solution IMHO is already in this thread.

ChumpusRex wrote: »

However, a small, roof based installation would be able to produce power during the day and sell it to the grid. Then at night, you could have the storage heaters buy in cheap power. This would be practical; but given the greatly reduced subsidy now available, you'd need a South facing roof for this to be viable.

Use the solar PV to offset your peak usage and draw in cheap electric at night to charge storage heaters. Look at Quantum from Dimplex to see how good they can be.

You can probably get some money back on the installation of the Quantum system as they are recommended by the energy saving trust.

http://www.dimplex.co.uk/products/domestic_heating/installed_heating/quantum_energy_system/index.htm

matelodave

You'd need a really really big one to store leccy or heat generated in June-September to be able to use in between January and March:) Batteries might but they'd also be totally uneconomic as I, for instance would have to store about 4-5000kwh worth of energy and that's a hell of a lot of batteries.
Several weeks worth of snow as we had in 2010 or an extremely prolonged cold winter like in 2012 would muck up your calculations a bit as well so you'd need a bit of contingency unless you take it from the grid.
All these things are possible but not very practical and definitely not economical. You might be a happy green person though