So the UK National grid (peak consumption hits 63GW, capacity 80GW - 30-40 million kettles respectively ), great though it is loses 7.7% of power due to heating, resistance, people retrieving their footballs from substation enclosures, etc... basically it's all due to the distance power has to travel.
Additionally, Rural areas in stormy conditions can often lose power due to the 11kV lines you see on telegraph style poles running alongside country roads being hit by weather/falling trees/lightning/cows. Powering and maintaining the rural areas is a bit of a mission in general for the 'Grid. Some people will have a backup generator; Good for them. Those who can afford a grid connection to the middle of nowhere? Well done. It's expensive!
Disaster strikes: the network stays up, but Russia stops the gas...What happens?
Whether the grid can't supply enough power to homes, industry, infrastrucure and more importantly hospitals due to
A) not enough power being produced due to reliance on imported fuel or
B) if it's as simple as there's a break in the circuit
Microgeneration is most commonly used to refer to the ability to produce electricity on a "small scale" (up to around 1-2 MW is considered microgeneration) for either owner's use or to sellback to the grid. That's how I'm using it here.
Renewable microgeneration
The general public and industries are starting to take notice of Renewable Energy - solar photovoltaic and more specifically wind power are lauded as the saviours of this planet by the popular media. However; economically (£ per kiloWatt) they're pretty inefficient: Wind turbines are always subsidised, and have you seen how much sloar PV cells cost?!
Here's an example from an interesting blog/site:$10,000 per kW... This well pitched site says UK houses will use on average up to 9ish kilowatt hours (kWh) per day (7kWh for your standard 2-3bed) and with 9 hours of useable sunlight in a good UK day meaning your minimum investment is $10,000 - which due to UK pricing generally equates to £10,000. This is also subsidised to encourage use/make it affordable.
Solar thermal can reduce the need for as much electricity but is not strictly microgeneration. I'll cover it in another post.
Wind power can be generated very cheaply if you want to build your own windmill(youtube vid of one in action)- but legistation will be down on you like a ton of paperwork unless its in the middle of nowhere, and they aren't massively efficient; ie not at all efficient, and shop bought products are ludicrously overpriced for what they are (see David Cameron for details!). The UK is simply not windy enough. Good for caravanning though!
Wood and waste fuelled microgeneration.
Germany and Europe in general is very into its microgeneration. The UK isn't.
We have roughly 4 million tonnes suprlus straw, 1 million tonnes surplus wood from forestry and 27 million tonnes of landfilled waste per year; equivalent to around 10 million tonnes of coal in un-utilised energy sources. They are however very distributed. Efficient collection and transport is the problem with using these dispersed fuel sources in what's known as a centralised electricity network, running off few huge power stations.
Microgeneration solves this: give every large town the ability to deal with its council's landfill-bound waste (avoiding a £150/tonne penalty payable to the governement for landfilling), or agricultural biomass surplus using whats known as CHP - combined heat and power.
The electricity generation capacity of CHP units is normally slightly reduced due to economies of scale seen in centralised powerplants, but having a unit close to a town allows the provision of the rest of the normally wasted heat(up to 85% ish efficiency) as heat supplied to buildings/industrial processes in the form of hot water or steam. This has worked very effectively in new residential developments in Germany. Their CHP tends to be fossil fuel or compressed wood pellets, but the waste problem and space limitation of living on a small island with 60,943,912 (July 2008 est.) residents means that wood isn't necessarily the UK's best fuel to start with. I'm all for reforesting (Please no plantations - they are ecological deserts in most cases) but it will take time to reforest whereas the waste and technologies are already there. For example in South East London: SELCHP
Decentralised power production outcomes
Now imagine we're working on a more decentralised power network based on microgeneration with appropriate CHP;
- General demand is reduced - 60% of power in the home is used for heating so CHP schemes reduce the load here (also why I left off solar thermal earlier)
- The same microgeneration can be built to enable tri-generation where both heating and cooling can be used - reducing power demand during hot summers and for refrigeration units
- If part of the network fails, there is less impact across the rest of the system/to society's day-to-day functioning
- Management is more awkward, but that is because the current 'Grid system was never designed to manage lots of small-scale generation. A new management system could solve this
- Many of the plants would (should, but you know what the government is like about selling utilities) be council owned (waste disposal based) and this would save money for the council, both in terms of power bills, but also in not paying for landfilled waste. Sales of heat and power allow councils to cover costs, and free up money for other areas.
- People will have to become responsible for their resources. It seems a negative, but it is vital to securing our energy for the future.
- The government is behind the ideals, even if it hasn't acted yet.
Hopefully some food for thought there! Comments welcome.
Next post: Wood gas technology rundown
Next next post: Why I haven't mentioned Carbon yet...
Until next time,
Timmy
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