Cyprus-Forum.com

[devil]

Sorry to prevaricate, but there is no cut and dried answer to that question. This is because the efficiency of them varies enormously. As an approximation, with modern practical panels, the DC efficiency is typically about 15%, so this would give about 150 W/m² at reasonably full insolation (i.e., facing the sun between May and August between 10.00 and 15.00). However, most panels are between 0.6 and 0.8 m², so this figure is for the active area, not including the frames and it assumes the temperature of the panel is <25°C (the efficiency drops at higher temperatures). Then there are other factors, such as dirt/dust on the glass and humidity in the atmosphere, both of which will reduce the radiation.

In practice, for a S-facing panel mounted in an unshaded location at an angle of 35° from the vertical, you would be wise to count an average of ~120 W/m² for midday output on clear days, IMHO.

[Nikitas]

FInally i have a straight answer- thank you!

I had been applying a personal rule of thumb of about 100 wats to make caclulations easier. Now I can figure out how many of the things are needed to cover the house electricity bills. New law here in Greece allows consumers to sell electricity to the Electric Company as long as it is produced by reneable sources. We have nice southern exposure but the town planners in their wisdon allowed the street to the south of us to build houses one story higher than us. Still, there are several hours of sun exposure daily. And if I had a big enough plot of land and capital to spare I could invest in a solar farm, but that plan will have to wait.

Devil, if you reside permanently in Cyprus you could look into solar powered desalination. It stumps me how an island surrounded by the sea, with plenty of sun all year round can have a shortage of water. There are several deslalination plants but as far as I read in the media they are conventional powered reverse osmosis jobs.

[devil]

Yup, they are RO which are energy-hogs and CO2 emitters, but there is no real alternative. Solar flash stills require too much land. Fine for Saudi Arabia which has no problem with land area in the desert, but to cover one-tenth of this island with solar heaters to supply enough potable water for the population is just not on the cards.

It would be a much better idea to a) stop accidental leakages (10-20% of the total) b) regulate the use of wells and boreholes c) recycle used water d) have continental plumbing in houses, scrapping the old English method e) install grey water systems in all new constructions with roof top collection and road collection. These five measures alone would mean that we could dispense with desalination because there would be enough water for everyone twice over.

[Nikitas]

Devil,

Interesting perspective on water. You say enough water twice over, that would include the agricultural use? Farmers are major water users, from what we hear the heaviest users.

We get RIK news here in Greece and that is how I keep in touch with what is happening in Cyprus. Recently, during the presummer water warning period, the Minister of Agriculture stressed that grey water use is actively promoted on the island. Was that just political self advertising or is it actually used in new buildings? And what is continental plumbing?

[devil]

I don't know anyone who has grey water. Unfortunately, it does not lend itself to retrofitting but it's easy on new constructions. I believe there is a subsidy available, but it is probably bureaucratically quasi-impossible to obtain, like many other subsidies. One never sees it in the newspapers (English language) that I have found. Continental plumbing does not have unpressurised cold water tanks with ball cocks but goes through a check valve and pressure regulator. This means that both hot and cold water is under constant pressure at all times and decent plumbing ensures that there is minimal wastage with circulated hot water (little waiting for the shower to reach temperature or temperature changes when someone opens a tap elsewhere). The plumbing here is the antiquated system that the UK had since time immemorial.

You can have a look at thisfor a view on water and how it is wasted by incompetence.

[CopperLine]

Nikitas,
You might find the following sites useful regarding PVs. The first is a commercial site but has a straightforward comparison of how much electrical energy you get for your square footage. (Look under Products > Solar Photovoltaics > Modules. The second site is a US-based construction industry advisory service, where, if you look under 'Zero Energy Homes' you'll find a host of useful info

http://www.photonsolar.com/products/spv-modules.htm

http://www.toolbase.org/Home-Building-T ... pv-systems


Cyprus is ideally suited to exploit (and develop) PV technology. Latest 3rd generation PVs have up to 30%+ conversion efficiency but at the moment are expensive to manufacture. However the point to remember is that PVs require little or no maintenance, are simple to install, and have a working life of c.25 years. The best thing that Cyprus could do for itself, in energy terms, is for all commercial and residential building permissions to be dependent on minium PV self-generating capacities.

[CopperLine]

You'll find a reasonably clear non-technical response to the thread question about rubber pollution here :

http://www.theecologist.org/archive_det ... nt_id=1002

[The Microphone]

Who needs the Open University with this lot around????

devil....I'm pleased for you that you gave Einstein a run for his money! Well done on those awards. I'm sure they mean something. Perhaps you can create a 'how to clear litter from the central reservation of the highway' scheme.

Not looking at tons of discarded plastic bottles and other detrius would be a step towards a better environment.

If you start this scheme up, the next time I see a guy picking up said litter I'll cheerfully toot my horn. If that person is you, kindly wave back. You'll know its me coz i'll be doing just over 20mph and not choking from being unable to breathe from my excessive speed, but gasping for air but choking on the exhaust fumes of the mazda pickup that's overtaking me.

Heres to a better world!

[devil]

I agree that the rubbish thrown out of cars is a disgrace. Perhaps the £500 fines should be imposed from time to time. Ooops, sorry, that would mean the police would have to do work and take them off serious crime work, assuming the culprit wasn't the coumbari of the cop's superior. Of course, when I see empty ½ l water bottles thrown out of the window of a police car, I start to wonder what the point is of having police (and laws) at all.

Enjoy:



taken from this website

[The Microphone]

We're agreed on something then.