Macro- vs micro-generation

I was thinking the other day about how the electricity-generating landscape will be different in the future. There seem to be two sides to this: large power plants, generating a large amount of power for a large number of people (macro), or households and businesses generating their own electricity (micro).

There are many good arguments for both sides, and clearly as both exist as markets (there are both large offshore wind farms and small-scale solar systems being built, for example). However, I thought I would have a look at the arguments for both and see which I think is a more realistic option, if we had to pick just one.

I must apologise that this post may be lacking in numerical backup: I am writing this in a (rare) break from revision, and wish only to give an indication of the pros and cons for each, without concrete numerical evidence.



Firstly, I will look at macro-generation. This refers to the large scale: nuclear power plants, offshore and onshore wind farms, solar (PV) farms and so on.
One of the main advantages of these generation systems is that we can choose their location. This is important for two reasons: people are more likely to complain about a power plant close to them ("not in my back garden!"), and we can choose a location which maximises the electricity-producing potential. This is particularly relevant for the renewable sources: for example, we can put large wind farms offshore where the wind is much stronger, and so generate more electricity per area. Another good advantage is that a large system is less likely to be intermittent: the peaks and troughs in energy production by renewable sources can be flattened out by reliable and predictable sources such as nuclear power (I am planning to discuss the future of nuclear in a future post), so that there is less chance of an powercut than with distributed electricity production.
However, there are also disadvantages with macro-generation. Large power plants have to be put somewhere, and in the UK at least there isn't really a place (onshore) that isn't in "someone's back garden". This slightly amusing figure from Without Hot Air (Figure 18.8) shows the catch-22 of onshore wind farms- we can't place them too close to settlement centres, and conservationists will take issue with large industrial power plants in "tranquil" areas. This isn't a problem with offshore wind farms, but they have their own problems: difficulty connecting to the grid, for example.

We now look at micro-generation. This involves setting up houses and businesses with the ability to generate their own electricity on a small scale. Doing this can save a household or business a lot of money, particularly with the recent "feed-in tariff" schemes in the UK. At the moment, however, it doesn't look like micro-generation is capable of powering an entire economy: there are very few households living "off-grid" by generating their own electricity completely, let alone businesses, and these people tend to be extremely energy-efficient anyway- something that would require the rest of us to have a massive change in behavior which, personally, I think is unlikely to happen.

Despite this, could micro-generation be a useful supplement to macro-generation as a way to both take some of the strain off the large generation systems and enable people to be more responsible for their own electricity? I think that systems should only be installed and used if they are actually going to make a difference: there's little point in setting up a small-scale wind turbine in an area in which it's barely going to generate any electricity, for example. My view is that micro-generation can supplement macro-generation, but it is macro-generation that will provide the biggest change in energy generation in the next 30 years or so.

There is also another question: how macro should we go? I have been discussing country-wide here (UK), but electrical power currently in the National Grid doesn't always come from the UK: there are cables connecting us to mainland Europe, and plans are being drawn up for a "Supergrid" across Europe (at least, North Sea countries). It remains to be seen whether these plans will be put into action in the near future, but it's certainly an interesting thing to consider.