OilPrice has quite a good article here:
When estimating power costs and prices some very basic relationships are often forgotten in the enthusiasm for big powerplants and their efficiency in generating electricity! Most often the truck that runs you over in the ally is: THE POWERGRID.
A powergrid is a huge investment in not only copper – or rather in the last couple of decades – aluminum. Aluminum does indeed have a slightly higher electrical resistance; but it is lighter and thus easier to hang as overland cables.
Digging cables is expensive and broken cables are not quite as easy to find; but cables are capacitative - which means they “twist” alternating current the same way a capacitator does – a power line in the air “twists” the current the other way like an electrical motor does (inductively).
This means everything else being equal dug in cables is advantageous, as most electricity use is inductive, so it actually counteracts the twist electro engines give. Mismatch in “twist” causes energy lost as heat.
Material and phase of the current is however minor considerations in investment, as reasonably competent engineers have solutions for that. Just if you ever wondered about the specifications on your electricity bill - “twist” is generally billed separately.
To the bigger bucks:
If an electrical grid has grown with industrial and urban development it consists of an awful lot of consumers and quite many smaller generating plant – these plants may not be of the most recent date and could do the job more efficiently with the most modern technology.
But this sort of grid is normally very little sensitive to variations in consumption and fall out of generating plant (f.i. due to maintenance) and the optimal generation is normally secured by using the older plants as standby and only used during peak hours.
That changed with the nuclear power plants which generates a huge amount of electricity that has to be transported a long way (people don’t like living next door to such contraptions – Chernobyl might explain why). This means an expensive grid to transport the electricity as not only will the grid from the smaller plants have to be used, but the transport to the distribution center is added.
To make things really nasty, there is the question of vulnerability. The Ignalina plant in Lithuania is of the same design as the Chernobyl plant and it was for years a priority to get it closed down – especially in the neighboring countries – but that was easier said than done. Due to the central planning of the Soviet Union Ignalina supplied 3 countries with power – and no alternative to that could be put up with short notice.
It became a major EU program (in total around 3 bio Euros in compensation costs etc.) and involved electricity imports from neighboring countries, where Lithuania formerly was a net exporter. So much for cheap energy!
Wind turbines pose additional grid problems:
Not only do you have the distribution grid FROM the plant to the consumer; but also a collection grid from the turbines TO the distribution center.
The grid also has to be rather heftily dimensioned, as wind generation varies wild with the weather conditions, so it has to take a higher peak load without frying the wildlife.
This fickle production has to have somewhere to dump the excess, as the fossil fueled generators really love a constant load and rotations per minute in order to get the maximum efficiency. That problem is manageable if you already have a district heating system supplied by the exhausts from fossil fuel plants – then it just to dump it there as in giant coffee cooker.
Believe me: You get a lot of livid customers if an overload blows all the fuses in the city!
But building a district heating system is an investment that has a hard time paying off – especially in rural areas. The best thing to use with wind turbines (that can never stand alone) is hydroelectric plant as they are comparatively easy to regulate – except in Sweden, where a good century of hydroelectric generation has the water magazines down to 3 weeks of supply – tops. That was also the reason Sweden chose nuclear power.
One thing that makes my toes curl is the “environmental activists” with all their half baked insight, enthusiasm and political correctness. Power supply investments are hugely complicated - and even with the best of planning things go awry.
F.i. when Denmark got slammed with the first “oil crisis” it was decided to build nuclear power – every long haired and bird brained wanted a say. It was decided to build the power plants – and have Danish Rail convert from diesel to electricity to get a large rather centralized consumer from the get