is PV worth it - 9 panels facing west

[Worcester]

Since Installing our Immersun at the end of August we've saved / not exported / diverted / used 539kWh (depending upon what you want to call it)

 

[FB.]

With the immersun, crank the thermostat up higher to increase storage capacity and if required for safety get a thermal balancing valve fitted on the tank outlet.....

Is an Immersun worth it, for 1900kWh per year?
Especially if the water can be heated by gas for half the cost.

Not to mention the possibility of the Immersun not making use of the power because the water may already be hot, or on the numerous days with heavy cloud cover the Immersun may not be able to kick-in much, due to the system not reaching the 100W surplus output threshold.
In reality, I would expect 50% to 75% utilisation from Immersun, with 25% to 50% unable to be used because of the above.

That makes for a several-year payback. Will Immersun prove to be reliable, or will it be just as unreliable as most modern electronics, which have a lifespan of about five years?
A lot can happen in several years - Sharp and Panasonic/Sanyo currently teeter on the edge of administrators taking control due to high debts and low profits or even losses.
Only a few days ago, Panasonic/Sanyo was downgraded to a creditworthiness rating of "junk", and Sharp were similarly downgraded a few weeks ago.

 

[Worcester]

And your PV alone is a MUCH longer payback, if you add in the Immersun it reduces the overall payback time. Especially if as we are - on oil.

For real world results vs gas, see the posts by Brian Wright22 starting around here: PV immersion heater proportional control


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[TedM]

@FB The Export is DEEMED at 50% (for =< 30kWp) i'ts written in the legislation. Just becuase smart meters COULD read export, there is nothing in the legislation to allow them to change to measured export.for your FiT payment.

Actually the legislation says that deeming only applies if there is no registered export meter in use. So if the supplier registers the SmartMeter for export as well as import then the readings from it would have to be used for calculating FiT export payments and the deeming would stop for that particular installation.

I would expect most, if not all, suppliers to register any SmartMeters they install over the coming years for both import and export where there is existing microgeneration on site. Assuming they get their act together and don't fit SmartMeters that are not capable of measuring export - which has already been happening.

 

[Simpsod1]

I too had a bit of a dilemma regarding the do I or dont I luz £5000 on a 2.5kWp system on a SSW roof....
I did and was amazed at the output and generation during the summer months and moreover the difference it made to the electricity consumption.
Im looking at about £600/year in terms of FiT and money off my energy bills, but a lot depends on the way that you use the generated power for the latter.

Simple changes within the home, putting the wahing machine and dishwasher on only during daylight hours and not at the same time, the same with the electric cooker, switching to cooking more in a slow cooker (130w/hr) making sure that things are "off" rather than on "standby"
This graph shows this year vs last year energy consumption off the Norweb Federation, my PV system went live in July, though we had already made some lifestyle changes in the summer months which seem to be reflected in the June consumption data (LED lighting, smart switches etc).

Prices for PV installs do seem to be coming down, my friend paid £9000 for a similar install 12 months before ours and of course is on the 40-odd pence FiT, we paid £5000 an are on the 21pence FiT, now that the FiT has dropped again I expect the prices to have shrunk a little more.

Re: The Immersun, we have one and whilst this month has been disappointing (see "its dropped off" thread) it makes a blinding difference to hot water generation and I am confident that next summer I will be able to shut off the GCH completely...

I had the same dilema but with a east facing roof and £6k on a 3.25kw system - we took the plunge and to be honest have never regretted it.

We are on target to hit 2450KW for our first year earning us £560 in FIT payments, our electric savings will be around £140 per annum (and we already had low energy lighting everywhere - even the cooker hood)

It takes a bit of effort to maximise savings - have washing ready for sunny days etc, but just having the panels promotes a mindset that in itself is a more effiecent one!

 

[Worcester]

@Tedm I'm going to start a new thread on deeming as it could do with discussing in light of your contirbution.

 

[Danlow84]

The best way to know if your going to get a good deal is by having a free roof survey as then they can give you accurate facts and figures so you would know exactly how long your return on investment would be and how much you would be looking to save and make.IF anyone interested in free no obligation roof survey then get in touch.

 

[Danlow84]

Also in regards to panels for hot water then if your wanting any more info in regards with thermo dynamics ill gladly help as unlike a lot of companies we actually provide a panel that runs of atmosphere and doesnt need to go on roof it works 24 hours a day all year long and works in any weather condition and actually works better in the rain so perfect for our climate

 

[Andrew54]

The best way to know if your going to get a good deal is by having a free roof survey as then they can give you accurate facts and figures so you would know exactly how long your return on investment would be and how much you would be looking to save and make.IF anyone interested in free no obligation roof survey then get in touch.

Oh, I'm on with a couple of surveys Danlow, but it's still a tricky decision. They cannot give me accurate figures as to how much of the generated energy I can use myself - it depends on my lifestyle. And they can't accurately predict how many years payback makes sense - will I still be alive in 13 years time????? (I'll be 59 next month).

So please don't lie to me by saying you can produce accurate facts and figures, it comes down to opinions and guesswork.

 

[Andrew54]

Also in regards to panels for hot water then if your wanting any more info in regards with thermo dynamics ill gladly help as unlike a lot of companies we actually provide a panel that runs of atmosphere and doesnt need to go on roof it works 24 hours a day all year long and works in any weather condition and actually works better in the rain so perfect for our climate

"a panel that runs of atmosphere" ?????????????????????????????????????

 

[Danlow84]

I bull you not if they know how much you normally spend on your electric bills and they know what size system best suits you they could and should give you facts and figures to the penny and also the exact time period for your return on investment and dont be put off by your age i know people in there 80s that still buy panel systems.were are you based yourself?also yes the thermodynamics systems we use run off the atmosphere in any temperature down to -15degrees so works all year long to provide people with constant hot water and also only one panel needed.

 

[zeljuga]

Space shutle in black .It ments runs out of Earth atmosphare to infinity.

 

[Danlow84]

I can assure you they run of atmosphere they extract the heat from atmosphere day and night 1panel can provide a family of 4for hot water all year round.check out our website solarstyleuk.com or inbox me for a further chat

 

[FB.]

I bull you not if they know how much you normally spend on your electric bills and they know what size system best suits you they could and should give you facts and figures to the penny and also the exact time period for your return on investment

Exact amounts are not possible - not least because we don't know what the price of electricity will be in five years time, nor do we know what inflation will turn out to be, from which the FiT rats are annually adjusted.
Also my electricty usage habits will change over the years.

We can make a guess, but the further out the guess the more prone to random variation it will be, and, most likely, in 25 years time we can all look back and laugh at just how inaccurate some of the projected rates of return turned out to be.

My post #4 on this topic is probably a realistic and unbiased estimate, based on observations from my solar array and the arrays of many others (I am not in the business of selling solar so I can "tell it like I see it").

 

[Danlow84]

True in regards to rising energy bills but a sap calculation will give you accurate figures at current rates but all it means if energy bills rise again it just means the more money you would save and with the pv panels some people have even noticed them working off moonlight

 

[SolarCity]

True in regards to rising energy bills but a sap calculation will give you accurate figures at current rates but all it means if energy bills rise again it just means the more money you would save and with the pv panels some people have even noticed them working off moonlight

Moonlight? If this is true then I'll eat my own jaw and post a video of it on YouTube.

 

[Danlow84]

It all depends if its a full moon and posistion of moon as pv panels run off light not just sunlight so if moonlight strong enough it works and this isnt a fact we use to sell them this is what we have been told by customers who already have them fitted.

 

[SolarCity]

The only way I can even consider a system running off moonlight is if there was a huge amount of panels on a very small inverter - which would, of course, be pointless.

My offer of self-cannibalism remains.

 

[Danlow84]

Im not saying it works well but it does generate something.but the thermo dynamics do work very well in either day or nite

 

[SolarCity]

I've no doubt some photons are actually reacting with the panels and producing a tiny amount of potential energy but it needs to produce a certain voltage high enough to kick the inverter into life which is surely unlikely in moonlight?