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At last, it looks like we are on the way to a good debate here! 
I'll start at the end: I agree with GNEP that we would have to be very careful about harnessing ocean currents, even if it were possible. One of the problems is that they are constant in neither direction nor magnitude. If we take the Gulf Stream, for example, it moves N & S with the seasons. If we slow it down a little, there is just a chance that the underflow hypothesis may kick in earlier and cause W. Europe to have a new ice age. Then, of course El Nino actually reverses direction of one of the Pacific currents, whose name escapes me.
And you can bet your bottom dollar that the anti-nuke hippies would become anti-harnessing-current hippies, in any case, as they are anti-everything hippies.
I agree that wind farms (not necessarily offshore) offer the best bet in those climates where a consistent prevailing wind with an average velocity of 10 m/s or more occurs. Unfortunately, this happens only in the upper mid-latitudes (40 - 60 deg in both hemispheres). This means that a large belt from 40 N to 40 S is generally unsuitable for it. The Cyprus Electricity Authority has conducted a careful survey of the island and there is nowhere with an average exceeding about 5 m/s except for one small area on the S side of the Troodos mountains which is subject to diurnal katabatic winds of up to 6.5 - 7 m/s. As these turbines are non-linear, the output at 5 m/s is only about 30% of that at 10 m/s, so that it is doubtful whether a 1 MW windmill would produce an annual average exceeding about 300 kW, and this is not economically viable. You may think that it may be possible to have different blades on the turbine to operate at a lower wind speed, but the problem is that we also do have some very high gusty winds, so the wider blades would just break.
Of course, the main problem with wind is what happens on a calm day? Then we have to resort to thermal power. Denmark is the most wind-powered country in Europe with about 18% of its electricity coming from wind. They have discovered that they have unbalanced the grid by wind and its variability. They now calculate that variable sources (wind and solar) should never exceed about 15% of the total requirements, without putting an undue strain on the backup thermal system. For this reason, they have stopped all renewable subsidies. The Blyth affair is a more or less experimental offshore mini-wind farm with 3 or 4 (?) 2 MW windmills in NE England. It was chosen because of its ease of connection to the grid (near a thermal power station) and quite a windy spot. One of the problems discovered is that it upset Britain's defence system (the rotating 65 m long blades play havoc with radars!).
Yup! PV has not taken off very well because of its lack of competitiveness with wind and thermal. There is definite overcapacity and prices are at rock bottom, but still FAR too expensive. Current efficiency isn't too bad, at 120 - 150 W/m2. In climates like here, they would be ideal if cost were not an issue. In the UK and N. Europe, with half the sun and a lower angle of incidence, they would be even less likely to ever pay for themselves.
The theory that they require more energy to manufacture than they will ever generate in a lifetime is an urban myth. Their energy payback time is actually only a few months.
Someone evoked solar water heating. Again, it is ideal here and, in fact, I have it on my house. I need to switch on the immersion heater for an hour or so about 10 - 12 days per year for comfortable morning showers. It is GREAT! But, and it is a big but, we have a direct system that costs CYP 200 (GBP 220, USD 360). This means that, compared with the alternative of electric water heating, it has an estimated payback time of ~2.5 years, which is fine. However, the direct system cannot be used in countries which suffer from frosts. An indirect system is much less efficient and a typical system in the UK would cost GBP 2,000 - 3,000 and would provide sufficient hot water for a typical household for less than 200 days/year in SE England and less than 150 days/year in the Scottish lowlands. This is not economically viable, even if combined with an oil or gas fired CH system for the winter. For this reason, the UK offers a very conditional 50% subsidy on solar water heating, but even then it is not viable.
You may wonder how I know all this. I happen to be a member of the Engineering for a sustainable future Professional Network run by the Institute of Electrical Engineers (in fact, I was a founding member and on the first and second Executive Teams, from which I retired last year). These are subjects very largely debated on the Network.
I'll start at the end: I agree with GNEP that we would have to be very careful about harnessing ocean currents, even if it were possible. One of the problems is that they are constant in neither direction nor magnitude. If we take the Gulf Stream, for example, it moves N & S with the seasons. If we slow it down a little, there is just a chance that the underflow hypothesis may kick in earlier and cause W. Europe to have a new ice age. Then, of course El Nino actually reverses direction of one of the Pacific currents, whose name escapes me.
And you can bet your bottom dollar that the anti-nuke hippies would become anti-harnessing-current hippies, in any case, as they are anti-everything hippies.
I agree that wind farms (not necessarily offshore) offer the best bet in those climates where a consistent prevailing wind with an average velocity of 10 m/s or more occurs. Unfortunately, this happens only in the upper mid-latitudes (40 - 60 deg in both hemispheres). This means that a large belt from 40 N to 40 S is generally unsuitable for it. The Cyprus Electricity Authority has conducted a careful survey of the island and there is nowhere with an average exceeding about 5 m/s except for one small area on the S side of the Troodos mountains which is subject to diurnal katabatic winds of up to 6.5 - 7 m/s. As these turbines are non-linear, the output at 5 m/s is only about 30% of that at 10 m/s, so that it is doubtful whether a 1 MW windmill would produce an annual average exceeding about 300 kW, and this is not economically viable. You may think that it may be possible to have different blades on the turbine to operate at a lower wind speed, but the problem is that we also do have some very high gusty winds, so the wider blades would just break.
Of course, the main problem with wind is what happens on a calm day? Then we have to resort to thermal power. Denmark is the most wind-powered country in Europe with about 18% of its electricity coming from wind. They have discovered that they have unbalanced the grid by wind and its variability. They now calculate that variable sources (wind and solar) should never exceed about 15% of the total requirements, without putting an undue strain on the backup thermal system. For this reason, they have stopped all renewable subsidies. The Blyth affair is a more or less experimental offshore mini-wind farm with 3 or 4 (?) 2 MW windmills in NE England. It was chosen because of its ease of connection to the grid (near a thermal power station) and quite a windy spot. One of the problems discovered is that it upset Britain's defence system (the rotating 65 m long blades play havoc with radars!).
Yup! PV has not taken off very well because of its lack of competitiveness with wind and thermal. There is definite overcapacity and prices are at rock bottom, but still FAR too expensive. Current efficiency isn't too bad, at 120 - 150 W/m2. In climates like here, they would be ideal if cost were not an issue. In the UK and N. Europe, with half the sun and a lower angle of incidence, they would be even less likely to ever pay for themselves.
The theory that they require more energy to manufacture than they will ever generate in a lifetime is an urban myth. Their energy payback time is actually only a few months.
Someone evoked solar water heating. Again, it is ideal here and, in fact, I have it on my house. I need to switch on the immersion heater for an hour or so about 10 - 12 days per year for comfortable morning showers. It is GREAT! But, and it is a big but, we have a direct system that costs CYP 200 (GBP 220, USD 360). This means that, compared with the alternative of electric water heating, it has an estimated payback time of ~2.5 years, which is fine. However, the direct system cannot be used in countries which suffer from frosts. An indirect system is much less efficient and a typical system in the UK would cost GBP 2,000 - 3,000 and would provide sufficient hot water for a typical household for less than 200 days/year in SE England and less than 150 days/year in the Scottish lowlands. This is not economically viable, even if combined with an oil or gas fired CH system for the winter. For this reason, the UK offers a very conditional 50% subsidy on solar water heating, but even then it is not viable.
You may wonder how I know all this. I happen to be a member of the Engineering for a sustainable future Professional Network run by the Institute of Electrical Engineers (in fact, I was a founding member and on the first and second Executive Teams, from which I retired last year). These are subjects very largely debated on the Network.
(sorry). I was merely trying to illustrate that various parties are opposed to the proposed wind power project.
. my family built the house with two layers of these (results in walls ~50cm thick) - it stays cool (slightly above 20°) until end of july. and that was 20 years ago, nowadays there are far more advanced methods of isolating properly.
wulfman!
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