The Great 'Get Paid To Generate Energy' Hunt

Sylvan

Cardew wrote: »

I really think we should!

If it was a sensible plan, surely having PV is not relevant - we would all have batteries and charge them from our mains voltage.

Many people have been doing so for decades already. They call us "motorhome owners".
The alternator charges the leisure battery at the same time as the "car" battery but if the vehicle remains more or less stationary for over three days it is necessary to pay the surcharge for a mains hook-up at a caravan site for one night, to recharge (or adapt a hook-up cable to recharge from a 13A socket at home, which works just as well).

Over the last few years many motorcaravanners have bought solar panels and inverters in order to dispense with the need for mains power. Last time I checked they weren't prohibitively expensive, though I've no doubt the high demand at the moment has inflated prices.

Obviously the amount of power used by the lights, the fridge and the central heating fan in a motorhome doesn't begin to approach the amount needed for a domestic fridge, freezer and central heating pump, but it's only a matter of scale.

noncom_2

Cardew wrote: »

Noncom.

My point is that with my £18,000 investment in a bank/BS etc it is an asset that can be recovered(cashed-in!) at any time(or at the end of a 3 or 5 year term - immediately if you pay a small penalty), together with any accrued interest.

A PV system costing the same £18,000 cannot be recovered. You have to sell the property and then we can debate if it will add value to the property, and by how much.

Your 'Green' issue is understood, albeit I suggest the motivation for most people in getting PV is financial, and that is the issue being discussed in this thread.

You are obviously correct in what you say. I suspect however, that the liquidity problem will reduce a little over time. As people become more aware of the advantages of micro-generation (particularly the financial saving tied to the house), mortgage companies may come to see them more like other home improvements. Thus the value of the house will be raised, not by as much as the system cost but significantly nonetheless, in exactly the same way as it would by adding a conservatory or loft conversion. A homeowner would then have the possibility of re-mortgaging against that added value if some of the cash were needed back.

Another possibility is that the "Green Mortgages" the Energy Saving Trust have talked about, or PayAsYouSave loans will become widespread, and the householder will no longer have to stump up the cash themselves, but instead have access to a loan specifically for the purpose, whose repayment costs less than the income from the FITs.

Finally, most of your arguments against investing in a Solar PV system seem to apply similarly to buying a house in the first place: it is expensive, it has poor liquidity, it requires money for maintenance, it will reach the end of its usable life one day etc etc. Many people however are able to see the longer-term benefits of home owning, and I would hope that (even ignoring the "green" imperative) many people similarly will see the benefits of micro-generation using FITs to make it financially viable, even if it's not the complete no-brainer some would like to imply.

I appreciate all your posts on these topics: it's always good to debate every angle before considering investing such a huge amount of money!!!

Andy

Cardew

If it was a sensible plan, surely having PV is not relevant - we would all have batteries and charge them from our mains voltage.

Sylvan wrote: »

Many people have been doing so for decades already. They call us "motorhome owners".
.

Which is exactly my point!

If you feel that a battery back up system to power houses(rather than a generator) is a sensible option, then there is nothing to stop anyone installing such a system.

Having solar PV, or not having solar PV, is not relevant to that decision.

Bungle1976

OK, as promised here are the figures for the pumps on my solar thermal... I have two pumps as mine is a split east/west system. The total run time for 12 months was 612 hours, the pumps are rated at 35 Watts each, so a total of 21.42 KWh. I don't have my per unit cost of electric to hand, but lets say 12p (can't be far off). Therefore the total cost of running the pumps over a year is £2.57 which I think in the overall scheme of things is pretty much irrelevant.

Just a couple more points:

1. Cardew, you quote the average 1000KWh figure several times, I don't dispute it but it will of course depend on how big the system is. If you have a larger than average system then you will generate more. I would imagine (not having your source of data) the average system to be 20 tubes on a south facing roof (this is what most sites seemed to quote on when I was looking). I have 30 split East and West, which actually means I start generating hot water much earlier and finish much later albeit at a slight reduction over a south facing roof at peak (i.e. midday), though with 30 tubes I still get more than 20 tubes would at midday.

2. 1000KWh of solar is not the same as 1000KWh of gas, I get far more bang for my buck from solar than gas for reasons already explained.

3. The £135 (ok, minus £2.57) a year gas saving will get bigger each year as gas prices go up.

4. You are right, eventually the kit will all be scrap, but it will be many many years down the road. Neighbours of may parents have a solar install from the early eighties (now THAT is early adoption!) still going strong. That is not to say there are not others that have problems but there isn't a great deal to go wrong with them.

Cheers

George

P.S. Cardew, I know I am not going to convince you, to be honest I wouldn't even try! Just showing the other side of the coin, that's all.

P.P.S. For the sake of clarity, again, I am not saying solar thermal is ideal for everyone or even most people. In fact with the FIT possibly coming in for thermal in the future I would think now is NOT the time to do it!

Sylvan

Cardew wrote: »

Which is exactly my point!

If you feel that a battery back up system to power houses(rather than a generator) is a sensible option, then there is nothing to stop anyone installing such a system.

Having solar PV, or not having solar PV, is not relevant to that decision.

No, but, conversely, the option of having a battery back-up IS relevant to the choice between having a professionally fitted system, connected to the mains, which would attract FITs and having a DIY off-grid system - which is the decision we were talking about.

clc5

Dave_Fowler wrote: »

In my post, I was comparing the pension income I have been quoted with and without the inclusion of an 18k tax-free lump sum which I could take. I was remarking on the ludicrous situation where the PV system appears to give me a 150% increase in tax-free income over the pre-tax income from the pension.

However, let us assume I take the tax-free lump sum and invest it as you suggest.

I'm not sure how you've come to your figures. My calculations show that if I were to invest the £18k at 3% compounded it would be worth £31,563 after 20 years. The £1,236 indexed linked (3% inflation) also invested at 3% each year would amount to £43,887 by year 20. The break-even year is year 15. I agree that it would be 20 years before I would break even if I just took the annual savings and did not invest them. Incidentally, the invested income would be over £18,000 by year 11 - not that it is likely that anyone would be foolish enough to keep £18,000 in a current account earning virtually 0% interest.

To explain the basis of my calculations:- With the PV system, at the end of the first year the income will be £1,236. By the end of the second year the FITs income will be £1,277 (1.03 times £1,236). The first year's income has also been invested and is also worth £1,277. (Total £2554). FITS income year 3 is £1,315 which with the invested years 1+2 equals £3,946. etc.

But the predicted fuel price increase is several percentage points above inflation. This means that the savings each year on the electricity I use does not just increase by 3% but by 3% plus whatever the fuel price increase is likely to be. I'm not even going to start to predict the increase, but if the increase were as high as 7% above inflation, this would result in the savings each year on the electricity I use increasing from about £138 in the first year to £435 per year by year 20 and almost £700 by year 25. This is not a vast amount, but has to be added into the equations.

But the total unknown is the income tax increase. Should income tax increase to 26%, the first year's interest on the 18k reduces from £540 (20% tax) to just under £500 after 26% tax.

But who knows? ...

Dave,

Thanks for the clarification. My calc was wrong due to an error in the spreadsheet I hastily devised. Have re-done my figures, again assuming investment return of 3% after tax and inflation of 3%:-

cumulative PV return / 18k invested
value at end of yr 10: £16127 / £24190
,, ,, 15 : £28043 / £28043
,, ,, 20: £43347 / £32510
,, ,, 25: £60301 / £37688

Have you considered the RHI scheme which is to begin next April? RHI payments on an air source heat pump would give a better return as the capital outlay would be much smaller. That's where my money will be going assuming the govt goes ahead with it.

Dave_Fowler

clc5 wrote: »

Dave,

Thanks for the clarification. My calc was wrong due to an error in the spreadsheet I hastily devised. Have re-done my figures, again assuming investment return of 3% after tax and inflation of 3%:-

cumulative PV Returninvested 18Kvalue at end of yr1123618540,, ,,2254619096,, ,,3393419669,, ,,4540220259,, ,,5695620867,, ,,6859721493,, ,,71033122138,, ,,81216122802,, ,,91409223486,, ,,101612724190,, ,,111827224916,, ,,122053125664,, ,,132290926434,, ,,142541227227,, ,,152804328043,, ,,163081028885,, ,,173371829751,, ,,183677330644,, ,,193998031563,, ,,204334732510,, ,,214687933485,, ,,225058534490,, ,,235447135525,, ,,245854436590,, ,,256030137688

My figures exactly! Interesting to see using the 3% interest after tax and assuming 3% inflation, that at year 15 the amounts are the same - to the penny!

Doc_N

clc5 wrote: »

Have you considered the RHI scheme which is to begin next April? RHI payments on an air source heat pump would give a better return as the capital outlay would be much smaller. That's where my money will be going assuming the govt goes ahead with it.

Very much an option. Particularly good for underfloor heating systems. Maybe the best option is both - using the solar PV to power the ASHP?

Cardew

Doc_N wrote: »

Very much an option. Particularly good for underfloor heating systems. Maybe the best option is both - using the solar PV to power the ASHP?

PV produces no output at night and relatively little during the winter when heating is needed.

The major income from PV is from the FIT and the amount you save from using the output in the property during daylight hours is a small percentage of the overall income.

PM1

Davey Browning - Going to build your house. I have just read a book by Kachadorian from my library about how to build it for least energy usage. Worth reading as it starts with the foundation. Unfortunately american though.