Solar panels

[Mike4]

I have periodically used the on line solar PV calculators to estimate the potential at my house for solar PV with and without battery storage. The last time I checked was maybe two years ago. Sometime ago, I decided to invest the money it would cost for the PV array into SSE shares (and before that, NG shares). The dividend pays for my electricity and gas use. Effectively SSE pays my energy bill.

I will still have the shares at the end of the PV array life. Whilst the PV would require ongoing maintenance and cleaning, then depreciated to zero. The shares will have hopefully increased in value and will continue to pay my energy bills for as long as I hold the shares.

Just another way of skinning the energy cat.

RVF

But not the carbon dioxide reduction cat, which is the whole point of subsidising the solar panel industry.

The government and industry muddies the water by promoting them as a way of saving money rather than saving the planet, as your logic illustrates.

[UncleEbenezer]

PS - Recently, UK grid supply was more than 60 per renewable energy anyway. SSE are certainly an increasing part of decarbonising my domestic energy supply.

RVF

You need to watch headlines like that, and ask what they actually mean. They tend to be deceptive in various ways: the numerator is inflated by including heavy carbon-emitting energy like biomass, while the denominator is helped along by taking a figure for household consumption that excludes commercial and industrial users.

But agreed, SSE does appear to have the best track record in its peer group.

[PhaseThree]

The only advantage of having batteries is to ensure continuity of supply. If you live in an area where the mains power supply is variable or unreliable, batteries mean you can continue your life style.
Roger

Unfortunately the standard PV/battery systems don't work like that. Both the PV and the batteries are "grid-tied". This means that the PV system is only active if the grid-side supply is also active. The reason for this is to protect those working on the grid during a power-cut from electricity being exported from installed Pv systems. To continue to operate during a powercut homes systems must isolate themselves from the grid and switch to an internal AC frequency reference. This adds significantly to the cost of such systems.

[AsleepInYorkshire]

I had an idle few moments last night so decided to revisit the cost of a rooftop 4kw solar panel array. The first ad that came up = £3900 for a 4kw fully installed and certificated Solar panels and battery systems.

From memory, this is a huge reduction on the cost of a similar installation, say, 10 years ago (and I'm sure there's better than £3900 out there). I'm assuming most of the customer friendly government incentives / tariffs have disappeared though. I'm not looking for anyone to do the research for me, but at first glance, it would seem that solar panels are a better deal now than in the past?

A quick question or 2 though, I take they still buy the excess electricity from you and it's possible for the panels to charge storage heaters or an electric immersion water tank? And I'm assuming a 4kw system is still the maximum permitted for a domestic installation?

Cheers

Amongst one of my greatest achievements apart from an advancing longevity is the reducing amount of time I have to sit in the barbers chair. Not that I receive any reduction in rates. I'm baffled as many take the smeg out of my large shiny forehead. It's a solar panel for a sex machine

Now I know Mr Titanium leg (we would use cast iron in Yorkshire ) has chosen "sunny" Scotland as his abode. Can't really fault that. A beautiful land with some great distilled products. But I would like to raise a serious issue if may please. At this point I have to add a huge Caveat. I may not have a clue what I am talking about. I wonder if, because of it's Northern location, Scotland isn't a great place for Solar panels due entirely to the position of that big yellow thing in the sky? Clearly there will be less of an "energy source" in Scotland than say Kent. But I have no idea what the difference is and if it's negligible in the bigger picture? If it is then it may be worth considering additional insulation as a cheaper source of reducing carbon emissions?

Hope the leg's healing well and the better weather is allowing you to get out a little more.

AiY

[PhaseThree]

There is a great online tool for calculation PV performance for different locations.

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#PVP

There is a difference between Scotland and Kent. Scotland will produce 20-30% less for a given installation size.

[AsleepInYorkshire]

There is a great online tool for calculation PV performance for different locations.

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html#PVP

There is a difference between Scotland and Kent. Scotland will produce 20-30% less for a given installation size.

Wow - I didn't think it would be that much. Interesting stuff. Ta

AiY

[PhaseThree]

Thanks for thevgood wishes AiY.

My dilemma stems from the fact that I don't need the panels to generate 100% of my green energy. It's already totally renewable (according to my provider anyway).

So so I look at them for cost savings? Well while they have really come down in price, so the incredibley generous incentives have disappeared too.

Im kinda thinking its just not worth it. I'll just stick with what I have.

Have you considered installing sufficient PV to handle the "parasitic" load of your house ? In my case this amounts to around 500W 24/7 and is consumed by items such as Fridge-Freezers, Treatment plant, Ventilation system, and various consumer electronic items etc. A 2kWp system would cover this for me for during daylight hours for 8-9 months per year at a self install cost of around £1700. I calculate a payback time of around 6 years.

[AsleepInYorkshire]

Thanks for thevgood wishes AiY.

My dilemma stems from the fact that I don't need the panels to generate 100% of my green energy. It's already totally renewable (according to my provider anyway).

So so I look at them for cost savings? Well while they have really come down in price, so the incredibley generous incentives have disappeared too.

Im kinda thinking its just not worth it. I'll just stick with what I have.

You may not have the time or energy for it - but draught exclusion can dramatically increase heat retention. Obviously not between rooms but between external and internal. It's not expensive, if you do it yourself. But it isn't a quick job if done right.

Have you done the calculation to see how much carbon you don't use if you turn the heating off completely and go somewhere warm for winter? You could pay for the additional carbon you use through the airline?

AiY

[scrumpyjack]

We make all these efforts whilst Germany and Poland carry on burning coal like there's no tomorrow (which there won't be at this rate).
The Germans take hypocrisy to a new level, shutting down their nuclear generation and burning vast amounts of coal instead! I hope the Greens win their election but suspect they won't.

[gryffron]

Have you done the calculation to see how much carbon you don't use if you turn the heating off completely and go somewhere warm for winter? You could pay for the additional carbon you use through the airline?

Interesting suggestion. First result from google suggests modern aircraft are remarkably consistent at c40kWh/100pax.km. (Bigger aircraft are more fuel efficient but tend to fly further carrying more fuel). So flying 1 person to Spain and back (2,500km) is 1,000kWh. That's only one month's average gas usage in winter. Maybe we should all fly south for winter

Gryff

[AsleepInYorkshire]

Have you done the calculation to see how much carbon you don't use if you turn the heating off completely and go somewhere warm for winter? You could pay for the additional carbon you use through the airline?

Interesting suggestion. First result from google suggests modern aircraft are remarkably consistent at c40kWh/100pax.km. (Bigger aircraft are more fuel efficient but tend to fly further carrying more fuel). So flying 1 person to Spain and back (2,500km) is 1,000kWh. That's only one month's average gas usage in winter. Maybe we should all fly south for winter

Gryff

I'll let you know what the weather is like when I land there

AiY

[scrumpyjack]

But I thought the emissions from aircraft are far more damaging because of the high altitude at which they are thrown out. It isn't directly comparable with CO2 output at sea level.

[gryffron]

I think it has more to do with all the other muck they chuck out, not so much the C02. Gas is a much cleaner fuel. Nonetheless, there has to be a breakeven at which AiY's point is valid.

Did you miss the smileys?

[BobbyD]

Five years ago there was a big push in the automotive industry to enable the the batteries in electric cars to be used as buffer batteries for the electricity supply. The argument being that having a (big) battery in you car that was sat doing nothing while you charged and discharged a separate battery for you home supply made little sense. This would have required the Electricity operator to "borrow" the energy when needed (Usually at EastEnder's time) and replace it overnight when there was spare capacity.
This idea seems to have hit the "too hard to deal with" barrier as well as concerns about consumer acceptance, but it's time may yet come.

V2G is coming, at the car end at any rate.

“The test vehicles are running, we are in the last pulls with the preparations,” confirms VW Development Board Member Thomas Ulbrich in an interview with the Handelsblatt. From 2022 onwards, every electric car from the Volkswagen Group that is developed on the basis of the MEB (“modular electrification kit”) electrical platform can not only charge the electricity but also return it to the grid. In addition to VW, the MEB is also used by the sister brands Audi , Skoda and Seat-Cupra.

https://electrek.co/2021/04/06/vw-elect ... next-year/

From memory I think Hyundai/Kia also have something.

[PrefInvestor]

Our solar panels were installed just before the end of the FIT tariff in March 2019, as a consequence our FIT payments are much less than those who installed earlier. I estimate that the payback time is 20 years at least. Without the FIT payment it would be longer still and definitely not an economically viable purchase. My son is just having a system installed under one of these group schemes promoted by the council I think, price is about £7,000 for what looks like a good system.

And batteries are far worse than that, from my perspective anyway. Batteries cost almost as much as the solar PV system, supply much less electricity and are only guaranteed to last 10 years after which time you get to buy another one. I’m waiting to be able to use the battery in an EV (when we get one), no big fixed installation and you typically replace a car regularly anyway.

Self installation of a Solar PV system might be possible if you are a qualified electrician and are familiar with PV equipment I suppose, but going with a registered MCS Installer would be preferable IMV. The choice of the panels, inverter and the installation are all critical factors in a solar PV installation. Get your choices wrong or buy a cheap system which includes poor components and a skimped installation and you may just end up with a system that doesn’t perform well and which might even be an electrical and/or a fire hazard. So take care !.

ATB

Pref

[richlist]

We have free hot water with solar PV panels. The sun comes up, electricity is generated by the panels, the brain directs energy firstly to run the house, then any excess is sent to the immersion heater to provide domestic hot water. With the current sunny weather our water tank is usually hot i.e. it's reached its thermostat setting by 10am and the solar panels can get on with providing power for dishwasher, washing machine etc.

I think the hot water feature cost an extra £200 seemed like good value for money. Now I use far less gas heating the water tank.

[Mike4]

Ok, I've backed away from Solar PV.

So now I'm considering Solar thermal.

I remember a few year ago watching Dick Strawbridge down on a farm in the SW of England making a rather basic solar thermal setup using old domestic house radiators, painted black. It worked pretty well. A day in the sun and you had pretty hot water. A friend in Spain who lives 'off grid' used to just fill an extremely long hosepipe and lay it across his garden. Within a few hours, he had very hot (free!) water.

I have a 120l tank in the spare bedroom heated on Economy 7 (still 100% renewable according to Scottish Power).

I've seen kits on Ebay that start from a few hundred quid and there are grants for professionally installed systems.

Do take into account the legionella risk if mucking about designing a DIY system.

[PrefInvestor]

Well I didnt include solar thermal in our system, because I did some rough sums and concluded it wasnt going to be worth it - as follows.

I read my meters every week, have done for many years now. During the summer months the central heating isnt using any gas, so the only usage is heating the water. Looking at my meter readings it is clear that we use roughly 0.8 (varies a tiny amount but not much) of Unit of Gas each day to heat the water, all the while the CH is off thats the daily usage. I dont see any reason for water heating to be a whole lot different in the winter. So I reckon my annual Gas usage for water heating is 365*0.8 = 292 units, at 2.62p per Unit on my current Avro tariff that comes to £7.65 a year.

For that price almost ANY expenditure on a solar thermal solution is going to have a hugely long payback time and so be uneconomic I reckon.

Others situations may be quite different, but thats my view anyway.

ATB

Pref

[richlist]

The cost of hot water will depend on many things including how much hot water is used. Our solar water heating system uses 1.9Kw per day on average all generated by the solar pv.

I d suggest conservatively thats valid for 8 months of the year. Our electricity night rate is 8.74p per unit so potentially a saving of
£40 a year for those 8 months. We make less of a saving in winter as there is less solar energy.

[servodude]

Thanks for your reply

I dont see any reason for water heating to be a whole lot different in the winter.

The water will be quite a bit colder.

evacuated tube systems will normally use something other than water if installed where it gets to below 0deg C
they also need a great big heatsink where there's an excess of temp at other times of the year: swimming pools are excellent for this
- a friend's system didn't initially and the hot water tank would vent steam at 14bar (at head height outside his kitchen window)
- the "installer" fixed this with a 4' hose aimed towards the ground - which pointed everywhere else when it was in action
They are very efficient

-sd