4-5kw solar PV: advice please!

ajbell

It still hurts when I see it is exporting.

EricMears

ahw23 wrote: »

We should also be getting an electric car pretty soon but would need to charge it on weekday evenings some of the time.

We have an EV but very seldom bother trying to charge it using PV. In the last 12months that we've had it, it's travelled almost 10,000 miles and used 2000 kWh which cost around £120 with E7 power. I suppose that £120 might have been better in my bank account than my electricity supplier's but it's not a huge sum, it represents a saving of well over £800 on DERV and I'm prepared to pay that much for the convenience of being able to use the car whenever I want.

There were odd days in summer when EV battery wasn't completely full , we didn't intend to go anywhere and there was at least 1kW of surplus power so I did have a couple of hours charging at 5A (or even 10A if very sunny) but such days are so rare that they can almost be ignored.

ahw23

We're under no illusions about where the EV's fuel will come from. If we're really lucky, they will install charge points where my OH works (as they already have a few roofs of panels & a biomass boiler, so it's not out of the question). However, there's no doubting that it will push up our electricity usage, so every little helps.

pinnks

Hi,

Just realised that you live about as far away as I do from the firm I used for both of my systems. I was happy with the installs and would use them again. A quick look online suggests they are weathering the storm, post FiT changes and I did receive their newsletter recently, so again, I assume all is fine.

Take a look at https://www.eco2solar.co.uk and perhaps ask them for a quote. They are based in Kidderminster.

Edited as I just thought, you might like to look at my own consumption here - https://forums.moneysavingexpert.com/discussion/5471656 - and the ensuing discussion, when thinking about leccy savings you might or might not achieve.

Martyn1981

ajbell wrote: »

Got my comsumption down from 13000 gas, 3500 elec to 8000 gas and 900 elec.

That's brilliant, far better than me.

Not having a go, just playing safe. I did ask folk on the generation thread a couple of years ago if I should revise the savings up, but the majority (it might have been unanimous) said leave them there for now.

It was easier before when the FiT was higher, as people could see a decent return, even with a low leccy estimate, so anything on top was a bonus. But now the leccy savings are more important, so like you, I'm a bit torn on what to suggest.

ajbell wrote: »

I need a lower standing charge in the summer and something to do with the excess electricity, any ideas?

Have you considered a no standing charge deal like Ebico. The leccy is much more expensive, but you'll save those fees. Just multiply the price difference by 900kWh and compare that to 365x your current daily charge.

I worked out that if I had a batt, taking import down to 600kWh, then I'd save another £30 switching to a 20p/kWh NSC account.

Martyn1981

ahw23 wrote: »

I think I'll get on the phone to them again tomorrow and see if they can come out to visit. I don't think we can come to any conclusions about how much electricity we'd save, as there are too many variables. Our current usage is higher than I'd like- about 14-15kwh/day, not all of which I can account for (as our monitor broke at some point during the move). Hopefully, some of it is the electric shower, which wouldn't be so much in demand if we had iBoost and a mixer, and some of the rest comes from the insane incandescent/halogen bulbs left by the previous inhabitant. At the moment, there's someone around all but 2 days of the week, with plenty of cooking (all electric) and laundry (ultra-efficient brand-new machine) going on. We should also be getting an electric car pretty soon but would need to charge it on weekday evenings some of the time. It's possible that I will up my work schedule in 2 years time when the family member generating the dirty laundry and eating the hot meals heads off to school, but it's not definite. Even if that happens, we can probably still set dishwasher and washing machine on timers.

That's really interesting.

If you've read the conversations between me and ajbell, you'll understand why we are being careful not to mislead you. However, everything you've said, particularly your high(ish) consumption at 5,000 - 5,500kWh pa, suggests you'd be at the better end of savings, especially with a larger system. You should beat me in leccy savings (around 1,500kWh pa), perhaps risk a guess at 2,000kWh x your leccy unit price.

[Caveat - as I have a similar system (size, orientation and pitch) I have to repeat that winter gen will be very poor.]

This will help you both economically and environmentally in your decision.


Personal comment, but get rid of the halogens ..... today ..... the pay back on LED's is very cheap. I've bought some from Screwfix this year, and recently bought some GU10's and 'normal' lightbulb looking LED's from B&Q at 5 for £7, though the regular price might be £10, so £2 each. Payback should be 6 months if on for 2hrs per day.

Quick check, B&Q now in 3 packs, but Screwfix have great 5pack deals on, some less than £10.

ajbell

Yes, go for the LEDs today, I bought cheap ones (10w B22) off ebay well over a year ago and they are still going.
Way better than CFL and less than £2 each.


As far as the consumption goes you do have to change your mindset and think about how you can best use your generated power, as I have said a few times I hate exporting. I don't export at all now in the winter as everything excess goes to water and radiators but need something to do with 20kWh a day spare in the summer.

ahw23

Living in a village without any lightbulb purveyors on our routes to and from work, and with an exhausted toddler in tow at the end of the day, replacements are taking us a little longer than they would have a few years ago and we were going to pick some up at IKEA on Sunday, but now that I look at the website, they've changed the stock, so B&Q (£3 each) is cheaper. So far, we've shuffled what we have around so the worst culprits are in places we use least. There are 16 sockets for GU10s in the kitchen alone, and most of the CFLs were the fancy globe-shaped ones that are less efficient anyway. The bulb hanging low over the table was 116W, which was frankly like being interrogated. If you need any further evidence of the previous owner's ideas of efficiency, the central heating thermostat was set on 25 degrees and it was on round the clock. Ultimately, I'd rather get consumption down to below average regardless of generation, rather than keep using a lot so we can say we're saving money: it really bothers me that we're using so much when we don't even have a television, I batch bake and use the pressure cooker to keep cooking power to the minimum, and chose our fridge/freezer and washing machine based PURELY on them being the most efficient within our budget.

ASavvyBuyer

ahw23 wrote: »

Living in a village without any lightbulb purveyors on our routes to and from work, and with an exhausted toddler in tow at the end of the day, replacements are taking us a little longer than they would have a few years ago and we were going to pick some up at IKEA on Sunday, but now that I look at the website, they've changed the stock, so B&Q (£3 each) is cheaper. So far, we've shuffled what we have around so the worst culprits are in places we use least. There are 16 sockets for GU10s in the kitchen alone, and most of the CFLs were the fancy globe-shaped ones that are less efficient anyway. The bulb hanging low over the table was 116W, which was frankly like being interrogated. .

Take a look at the Screwfix site here http://www.screwfix.com/search?search=LED+G10#sort_by=price There are plenty under £3 each, or buy in boxes of 5 or 10 for a better price. If you buy enough you also get free delivery. I have found nothing wrong with the quality of their ones.

pinnks

There are loads of LEDs out there but by far the best I have bought so far for GU10 spots and 12V MR11 halogen replacements are from TP24.com.

I happened across them as I wanted some long barrel GU10s to replace some 13W CFLs. TP24 was the only place I found, so went with their 3W GU10s. Absolutely amazing! Really good colour temp so just like halogens in terms of light quality.

Some of our existing LED 12V spots were, let's say, floury and greenish to my eye, so decided to replace them with TP24 versions. Again, magic, and the bulbs themselves look good in exposed lamp holders as they are all glass like halogens. Only downside is when you drop one from 4.5m onto a laminate floor they don't survive - strange that :rotfl: but seriously I am so impressed that I changed all of the remaining MR11s.

They are not the cheapest at about £5 each but well worth the money.

I have also found some good 12V capsules on fleabay to replace those little halogen GU4 (?) capsules. 1.5W and 3W versions. 1W are good in the bathroom cabinet and 3W x3 for dining room ceiling and 5 x 3W for stairwell. They cost about 80p each from memory.

Final thing I did was change the AC transformers for LED drivers as the transformers were using more power than the bulbs just to transform. Again, picked these up on fleabay for about £5 each I think.

All told I have reduced our max lighting wattage if I were to turn on every light in the house from over 30kW to 3kW. Worth the investment of a few hundred £ in my view :T