Thats another thing people dont understand, they think advances in technology can solve everything, unfortunately no advance in technology can create energy out of nothing or harvest energy thats not there in the first place.
That's 3 kWm⁻² of rotor disc. But then you need spacing between turbines of 10 to15 times the rotor diameter ... which could be more than two kilometres in the case of the GE behemoths!
The solution is simply to suspend a doughnut of plasma at 100 million degrees Kelvin in a magnetic containment field (or electrostatically confine it...somehow) and generate nuclear fusion. Nuclear is the only viable form of green energy and fusion is the only version of nuclear which doesn't generate waste and is intrinsically safer than fission in that once the fuel source is removed the reaction stops.
Can you explain what the total electricity usage is globally? I see wildly differing figures. The figure of 18.0 terawatt-hours comes up. Is that the correct anual measure?Yeah, renewable energy tends to be fairly diffuse. 1.3 kWm⁻² is not bad for solar, but at 15-22% efficiency and the sun not overhead, you could be easily talking about 0.1 kWm⁻² of land use. Wind turbines can produce a lot of energy per unit area of the rotor disc. General Electric are creating the current largest -- 12 MW with 107 m blades. That's 3 kWm⁻² of rotor disc. But then you need spacing between turbines of 10 to15 times the rotor diameter ... which could be more than two kilometres in the case of the GE behemoths!
Can you explain what the total electricity usage is globally?
My question relates to the proportion of total electrical generation capacity which existing renewables can realistically handle. That is before we account for the massive amount of energy generated in vehicles using internal combustion engines which will, hopefully, one day be replaced by electric cars. Those cars will be powered from the Grid.Amount of energy used is not the meaningful measure.
The grid has to maintain an energy output per hour which is high enough to meet the demand plus any losses, at all times. The maximum output of the Irish electricity generating capacity is just under 8 giga watts AFAIK.
As most power stations cannot be turned on and off at short notice, and wind power which comes and goes based on the wind, the system produces at this level continuously (aside from the pumper storage facility at Turlough Hill).
Can you explain what the total electricity usage is globally? I see wildly differing figures. The figure of 18.0 terawatt-hours comes up. Is that the correct anual measure?
The USA is still by far the biggest emitter of CO2 per capita, but its total output is less than half that of China. North America's coal consumption has dropped by 40% in 15 years (because of the cheapness of natural gas, not any altruism!), while China's has doubled. Consider that India now uses more coal than the US and the EU combined, and China uses five times more than India! And Chinese and Indian consumption are growing at 3% and 5% per annum respectively. Nothing the West does to curb CO2 emissions will be effective in the face of such growth, though there's an argument for making the problem worse as slowly as possible.
Can CO2 be captured at point of creation, eg. From the chimney of a coal burning power station and recycled.
Convert it into methane and burn it again.
Maybe it is impossible to do ?
All true but in reality it all makes very little overall difference. The statistics for emissions from beef production are wrong in that they are calculated based on feedlot production rather than grass fed beef. Removing antibiotics from beef would greatly reduce their net CO2 emissions as their manure would then attract far more soil aerating insects which in turn increases plant growth and biodiversity.I see people knocking solar PV here. If everyone in this country had solar PV we could substantially reduce our requirements on imported gas and oil.
In my own case , I put in solar PV and my consumption of electricity from the grid will reduce by almost 2/3rds in a full year.
Multiply my example by every house in the country and you will see how small changes will add up. Even if they reduced their electricity use from the grid by 1/3rd or 50% that would be a substantial reduction.
So people can do a number of things including..
1: Reducing their meat and dairy consumption.
2. Take less flights
3. Walk or cycle where possible
4. Use renewables
5. Insulate their homes
Some of these will also have health benefits i.e. walking/cycling/reducing the amount of saturated fat we consume.
The options are not binary. For most people taking less flights is obvious and has been for years. People may not have been aware that the emmisons from animal agriculture is massive so it's good that people are made aware that their choices have effects on climate.
Who are Trinners?One thing re electric cars, I think the theory is you'd be incentivised to charge at night, and even add to the grid on arrival home (peak demand). The thing with generation being you need to meet peak demand, but a lot of the rest of the time there's spare capacity, so cars could act like a national battery stock. I'm wondering will we run out of lithium, but the likes of Trinners may develop the tech to solve that. China & India though..., while we should do the right things, one suspects are are urinating against the prevailing air movement.