So now I have a solar PV system how do I make the most of it???

orrery

nikkist wrote: »

We are looking at the benefits of Shade Greener and Life's Energy ie panels owned by us or not. Life's Energy have mentioned the iBoost for heating hot water but I am getting conflicting messages to what I was told now I am looking on line.

Has anyone got any real experiences that they can share?

Thanks

I have the similar solarImmersion unit. The comments regarding top fitted immersions are worth taking note of - if it is the short type.

I have one, and it restricts the usefulness of the device. You need either a bottom fitted immersion, or you'll need to replace the top fitted immersion with a longer one - 27" are commonly available, or they can be made to order (mine is 30"). You'll need to factor in the additional cost of that.

However, once I got the 30" immersion, as a rough indication I was able to turn off the gas boiler for about 1/3 of the year, and get significant contribution for another 1/3, with it doing next to nothing at the moment. So, on a summer's day it provides a bath and a shower every day for free.

michaels

WE have an iBoost, we have turned the gas thermostat down to 50 from 60 and the immersion thermostat to 75 - we are lucky our tank has 2 immersions, the lower one (3kw) is connected to the iBoost.

Since August we have put in the following monthly units into the hot water:
148
148
109
Tomorrow I will see what we have done for October, with 5 in the house we have 10 baths or showers a day so use a fair bit of hot water. I am valuing these units at about 4.5p each as although substituted gas is only about 3.2p/unit there are losses in heating the water with gas.

ChrisJD

michaels wrote: »

Since August we have put in the following monthly units into the hot water:
148
148
109
I am valuing these units at about 4.5p each as although substituted gas is only about 3.2p/unit there are losses in heating the water with gas.

So, what were your overall costs for the iBoost and its installation and when do you calculate it will break even?

michaels

ChrisJD wrote: »

So, what were your overall costs for the iBoost and its installation and when do you calculate it will break even?

It was bundled with system, list price was 350 installed but I suspect that without it price would have been 250 less. Breakeven? - I worked on 1000-1200 units pa at 4.5p per unit so the aprox 6-7 years which matches rest of install.

Sterlingtimes

Other point is that you can't have your cake and eat it.

I'm in the fortunate position when my usage of solar power generated is high. That leaves far less electricity available for diversion.

When I have a full year of export readings, I will know with more accuracy my actual performance. At present it is looking like 55% used 25% diverted and 20% exported.

Doc_N

michaels wrote: »

It was bundled with system, list price was 350 installed but I suspect that without it price would have been 250 less. Breakeven? - I worked on 1000-1200 units pa at 4.5p per unit so the aprox 6-7 years which matches rest of install.

Interesting. Having now had the system in for over 5 years (getting the highest feed-in tariff rates - but for the highest cost of installation) I'm curious as to the economics of these - which one to go for, whether it's worthwhile for anyone with mains gas, installation costs etc.

They always seemed expensive by comparison with the payback, but maybe that's starting to change?

orrery

Doc_N wrote: »

They always seemed expensive by comparison with the payback, but maybe that's starting to change?

I've seen the iBoost at £230 on ebay. It should be a breeze to install, as the detector is wireless, so:
- disconnect immersion and wire iBoost in line with it
- clip detector over wire to your electric meter

So, any local electrician should do that very quickly.

As for calculating the payback, that is really tricky as it depends on what other uses you have for your solar power e.g. using in preference to charge my electric car displaces the cost of petrol, where heating water only displaces gas which is cheap, especially when the boiler is already running to heat the house. In summer, it saves me turning the boiler on at all, hence a much bigger saving as I'm avoiding the waste of having to heat the whole system.

My advice would be:
- if you have have a bottom mounted 3kW immersion then just go for it as the payback is likely to be similar to the solar pv itself
- if you have a top immersion, then it needs to be a long one that heats most of the tank, not just the top. So, you may need to get a longer immersion fitted and the payback will be longer - probably 10 years or so.

michaels

Fitting is extremely easy, depending how your immersion is currently wired I suspect anyone with basic competence could do it.

October we only diverted 53 units but we do have an electric car that we charge during the day.

EricMears

michaels wrote: »

Fitting is extremely easy, depending how your immersion is currently wired I suspect anyone with basic competence could do it.

I absolutely agree.


However, people deciding to fit them need to have a very careful read of Part P of the Building Regs and satisfy themselves that they're not breaching them. I'd suggest that fitting a diverter unit into an existing immersion heater circuit is probably perfectly legal but that fitting a completely new circuit consisting of diverter and immersion might be considered a breach (and yes, I agree that it's a pretty silly distinction )

ajbell

If you are going to be using most of the electricity you are generating then does it make sense to choose a tariff with the lowest daily standing charge rather than pence per unit?.