Date published: 2005/09/25
The BBC says:
Small networks of power generators in "microgrids" could transform the electricity network in the way that the net changed distributed communication.
That is one of the conclusions of a Southampton University project scoping out the feasibility of microgrids for power generation and distribution.
Microgrids are small community networks that supply electricity and heat.
They could make substantial savings, and emissions cuts with no major changes to lifestyles, researchers say.
Electricity suppliers are aiming to meet the UK government's Renewables Obligation, requiring them to generate 15% of electricity from renewable sources by 2015.
Microgrids, say the researchers, could easily integrate alternative energy production, such as wind or solar, into the electricity network.
They could also make substantial savings and cuts to emissions without major changes to lifestyles, according to lead researcher, Dr Tom Markvart.
"This would save something like 20 to 30% of our emissions with hardly anyone knowing it," he told the BBC News website.
"A microgrid is a collection of small generators for a collection of users in close proximity," explained Dr Markvart, whose research appears in the Royal Academy of Engineering's Ingenia magazine.
"It supplies heat through the household, but you already have cables in the ground, so it is easy to construct an electricity network. Then you create some sort of control network."
That network could be made into a smart grid using more sophisticated software and grid computing technologies.
As an analogy, the microgrids could work like peer-to-peer file-sharing technologies, such as BitTorrents, where demand is split up and shared around the network of "users".
Microgrids could exist as stand alone power networks within small communities, or be owned and operated by existing power suppliers.
Campaign groups such as the Green Alliance have been pushing for micropower generation technologies, such as micro-CHP (combined heat and power) boilers - a vital part of microgrids - mini-wind turbines and photovoltaic (PV) solar arrays.
Micro-CHP units work by turning heat which would normally escape through flues into electricity. Homeowners then sell any surplus heat back to the national grid.
The Green Alliance says the government should take micro-generation more seriously.
Putting just six panels of solar PVs on a typical new three-bedroom house would reduce that household's carbon emissions by over 20%, according to the group.
Microgrids are designed for a smallish community - a typical UK housing estate for example. They deal much more efficiently with fluctuating power demands which the national grid is not flexible enough to cope with.
Nothing new here. Yes, decentralised power generation might be a good idea (it would certainly look like a good idea after a major terrorist incident at a large power station). But the technical details need to be worked out in a fairly rigourous way, and the sums done to make sure it makes economic sense. Unfortunately some of the dramatic language used in the article makes it looks like people have not thought about this seriously. First of all, a major requirement of any power supply is that it be secure, and if there are thousands of power stations attached to the national grid, then that opens up the potential of a hacker's paradise. And any article that mentions "grid" computing is obviously dubious, since "grid" computing is just the latest buzz phrase invented by academic computer scientists as a way of fleecing the research councils of money (because it sounds like such a great idea, whatever it turns out to mean). And don't you love the sentence "Then you create some sort of control network." If only it were that easy.
Further, putting solar PVs on a house in Britain right now probably adds to the global carbon emissions, when you do the full-lifecycle calculation, including the construction, installation, maintenance and disposal of the solar panels, and don't just look at the midlife benefits (i.e. when the solar panels are sitting on the roof of a house, producing electricity, not very efficiently). (Of course it depends on the discount factor used when doing the lifetime sums, although you could try using a discount factor of zero.)
Further, you have to wonder how anybody would ever claim that small power stations can cope with fluctuating power demands more flexibly than the national grid. The whole point of networked systems (for energy generation, the phone network, etc.) is that the larger they are, the smaller the proportion of extra average capacity is required to achieve a given level of service, because the fluctuations iron themselves out better in bigger systems. This is just simple probability and statistics. Of course maybe the BBC meant that if you have lots of little networked power stations then that is better than a few large networked power stations. That might be true.
_________________________________________________________
All material not included from other sources is copyright cambridge2000.com.
For further information or questions email: info [at] cambridge2000 [dot] com
(replace "[at]" with "@" and "[dot]" with ".").