solar pv

[ericmark]

Gosh, anyway, thanks for the diagram pasty. Whilst I too have reservations and hopes for the future, your question was simply about using an existing CU with a spare way. Given your description and the diagram, then I still don't see how you can put power into an existing CU without having problems with matching cycles if nothing else. I would have expected that the two power supplies need a joint terminus which would syncronise the inverter with the mains before supplying the CU or exporting. Or have I missed something?

It is not a normal inverter but a grid tie inverter and these auto synchronise with supply and from what I have read in last few days auto close down if incoming supply fails.

I would like to know more about inverters also. One big question is are they MPPT? (Maximum Power Point Tracking). It seems both solar panels and wind chargers give out the maximum wattage at different voltages according to the amount of sun or wind. By allowing the voltage to vary one can get quite a bit extra power and they will still produce with very little wind or sun rather than old style where they had a cut off point.

However for battery regulators loads of info but for grid tie inverters there seems to be very little. One would assume if they had MPPT they would tell us all about it so I assume they don't!

 

[ajstoneservices]

. One big question is are they MPPT? (Maximum Power Point Tracking).

They do.

 

[ericmark]

. One big question is are they MPPT? (Maximum Power Point Tracking).

They do.

Thanks I did look for that and it seems very few details are given. I have looked at grid tie inverters to boost the 4A available on my sons boat to the 10A he needs for his washing machine but lack of information means I can't forward the idea.

So tried using 4A to charge batteries and a 3Kw inverter from batteries. All well until inverter failed.

And this is the point 2 months and failed and so now left without low voltage power. Only extra low voltage is working.

 

[ericmark]

A thought can one add to the output of a normal inverter with a grid tie inverter?

If one has a 1000W inverter and I find I need 2000W one would need to replace inverter as one can't just put two together.

However could one use a grid tie inverter to add to the output of standard inverter giving the extra power when required?

I see two problems

1) Normal inverter would need to be sine wave which are more expensive.
2) Need 24v not 12v to run grid tie inverter.

 

[ajstoneservices]

Eric I don't know the answer to your question however, Stecca have string inverters that can be interconnected.
http://www.stecasolar.com/index.php?main|cat46d5adc27eed5_0|2

 

[ban-all-sheds]

Should make it law though that all new builds should have all south facing roofs covered (you can get solar tiles) and tied in

Better to have laws requiring better levels of insulation, high thermal masses on the conditioned side, heat recovery. Better to have laws banning inefficient lighting, equipment on standby, inefficient cars. Better to have laws ending the preferential treatment of airline fuel.

Actually, since it all boils down to how, and how much, people use energy, better to go for the really simple (in concept) idea of personal carbon allowances. Then if people would rather light their kitchens with 2" downlighters than ever fly again, fair enough. If they would rather drive a Range Rover than ever eat oranges again, then fair enough. If they are rich, and want to buy some of the allowance of a single mum so that she can better provide for her kids and they can have an extra holiday, then fair enough.

 

[mointainwalker]

Should make it law though that all new builds should have all south facing roofs covered (you can get solar tiles) and tied in

There are some German towns controlled by Green councils who are considering / have imposed this.

The first was was somewhere around Stuttgart: a major sticking point was it was a medieval town, bulit on a steep hill, with modern suburbs around the foot of the hill. From memory something like 25% miniimum of new/modified/ roof area had to devoted to pv. Can't remember anything about orienation.

This has caused major upset and legal challenges as opponents say the blue/black pv slabs are out of keeping with normal red tiles and disrupt the aspect/views of the medieval cathedral on the hill. Don't know latest state of play.

Germany introduced lucrative FIT's some years ago and they are now being substantially reduced. A major reason - apart from savings - is the tariffs were so attractive that people were clamouring to buy panels at any price. There was therefore no incentive for manufacturers to pass on cost-savings and the panels remained over-priced. Studies estimate this policy cost German purchasers a good few billion euros.

 

[madmole]

Ah but Ban-all-sheds that only applies if you beleive the hogwash about greenhouse gasses that they feed you instead of looking at the science and making your own conclusions

Did you know that if they banned every car on the planet tomorrow it woul only reduce atmospheric CO2 by 0.00001%. cars are not a problem or even a minor cause of CO2

Every human on the planet is producing 1 litre of CO2 a minute, Cyclists and joggers double that

Did you know that Sattalite shows the planet has been coolling, not warming since 98

Did you know that sea level that has very consistently risen 1mm per year for the last 150 years actually rose 0mm last year

Did you know that Ice core data consistantly shows the CO2 does not cause a temperature rise. What its actually shows is that a temperature rise leads a CO2 rise by around 200-800 years

The geological record shows us that we are currently at a low CO2 low temp period in the earths history

That the BBC has over 60% of its pension funds in carbon schemes, as does Al Gore

That there are only 3 temperature data sets used for all the global warming projections and 2 of these have been discredited. There are many hundreds of other temperature data sets, but they are ignored as they dont show what the alarmists want

Personally I think we should just stop polluting the planet and ripping up all the trees. Petroleum is too important for drugs and other chemicals to burn it all in the next 200 years

Our biggest issue is overpopulation. Why not let everyone do their own wiring so that the dumb dont reproduce. The intelligent will learn how to do it correctly and safely or will employ someone who does to do it for them

 

[ban-all-sheds]

Oh dear - another misguided person who thinks that 10's of thousands of scientists are wrong, who thinks that hundreds of national and international scientific bodies are wrong...

 

[madmole]

No, someone that has 2 science degrees and knows that thousands of scientists dissagree with Global warming. There are only about 200 very active scientists and 6 organisations that support it, but they are the ones who are favoured by the governments and people who stand to gain from carbon credits and hence get all the funding and publicity

Facts are facts. Draw your own conclusions, dont believe what you are told. Its funny how the believers have to fudge the data to support their cause (NASA and UEA). They cant attack the truth, so they attack non beleivers as deniers and sceptics

Truth is we just dont know. The natural variations are so great that they swamp any effect we may be haviing. What we do know is we are at the peak of an interglacial so temps could be rising or dropping. During the last 10 or so ice ages the temps have risen slowly and dropped quickly. They appear to be solar and orbit driven. Our suns activity has decreased more than expected in the last 10 years. The solar maximum in 2 years times looks like its going to me a low activity one and then we have 7 years of lessoning output

Hence the massive remarketing of global warming to climate change

 

[ajstoneservices]

Truth is we just dont know.

You were certain it was hogwash in your last post

 

[madmole]

The "we are going to use global warming due to CO2 as an excuse to tax and control you" is a total hogwash scam based on guessed computer models written by people with a vested interest and a dire shortage of evidence

As for "Is the planet warming or cooling overall?", we don't know. It changes too much. We can take an average but even so some areas are hotter, some are colder and next year it will be in different places

In the meantime I would suggest we learn how Science actually works. Ignore those who use bad science to prove their case, and cut down on how much we pollute the planet. Alternative energy cant be bad, as it removes our reliance on Russian Gas and the petroleum companies

I've calculated it would take around £7000 - £10000 to take our house off the grid. But this would mean changing a lot of our habits and you'd only need a bad winter to drain the batteries and need to top up the batteries
I suspect the cost of the winter top ups and maintainance, cell replacement etc wi;ll be higher than the cost of our grid supply. Insulation and cutting down use will be far more effective. Sending the kids to Uni this year will probably be our biggest saving!!!!

 

[pjcomp]

Does solar PV work or not? Yes, it works - it generates electricity. Does it generate enough to replace your grid tie-in? No. But that doesn't mean it's rubbish and should be ignored.

none of the renewable energy sources, in their current state, are like-for-like replacements for a grid tie-in, and probably never will be. but that's not the point. Microgeneration is about a number of small sources coming together to supply needs, about individuals or small communities generating their power.

Does the National Grid work? Yes, it supplies plentiful electricity. It relies on primarily gas and oil from overseas sources to generate that electricity. Will the grid still work - and generate enough electricity if our foreign suppliers decide to keep their gas and oil?

PJ

 

[1john]

Does solar PV work or not? Yes, it works - it generates electricity. Does it generate enough to replace your grid tie-in? No. But that doesn't mean it's rubbish and should be ignored.

none of the renewable energy sources, in their current state, are like-for-like replacements for a grid tie-in, and probably never will be. but that's not the point. Microgeneration is about a number of small sources coming together to supply needs, about individuals or small communities generating their power.

Does the National Grid work? Yes, it supplies plentiful electricity. It relies on primarily gas and oil from overseas sources to generate that electricity. Will the grid still work - and generate enough electricity if our foreign suppliers decide to keep their gas and oil?

PJ

I dont hink it is possible for the majority of people to be self sufficient on electricity without compromising on the way of life that they are acustomed to.
If anyone wants to make a change utilising the sun I think that using solar to heat stored water for bathing washing and the like is a much better prospect. If the sun can heat a copper tank of water a day then that would save you running an immersion heater at 3kW in the summer when the gas or oil boiler is only really used for this purpose, in the winter months the gas or oil boiler would be heating the water already as the boiler would be on to heat the house. All this goes out the window if you have a combi but common sense says to me that you could use a combi to heat a tank of water whilst the heating is on anyway and perhaps the combi hot water outlet could be used for a designated tap somewhere.

 

[pjcomp]

Agreed, we can't be self-sufficient without compromising our lifestyle. But that's part of the problem - if the Grid can't supply us with enough power then our lifestyle is compromised anyway. Am I the only one on here old enough to remember the years of routine power cuts? And that wasn't due to shortages, that was usually down to union action, either the power workers switching things off, or the rail workers not delivering the coal, or the miners not digging it up. Those days compromised our lifestyles, and we were nowhere near as reliant on electricity as we are now.

PJ