Microgeneration and why (I think) its awesome.

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

PS

You may notice I've signed up to Google's adsense. I'm broke, and it may just provide some additional reading to what I'm writing. No guarantees though lol! I'm not allowed to click the links, so if anyone finds anything worth me blogging about, let me know in the comments.

Madness: A new UK power plant running of US woodchips?

So I start writing this sat in the library during the easter hols (It's lovely and quiet in here!). The revival of my e-soapbox comes from an article I unearthed whilst researching my dissertation, and the explanation of the new power plant being built in Wales. I'll leave you to read my comment attached to the bottom of the article (assuming it is passed by site moderators; they may not like my views!)
http://news.mongabay.com/bioenergy/2007/11/uk-approves-worlds-biggest-350mw.html

An analogy to carbon neutrality:

If I said I ate beefburgers to reduce the number of cattle producing methane (IIRC 27 x the greenhouse of CO2) and so reduce "climate change" (read: man's impact on atmospheric chemistry) then you'd say:

"Tim, you're a bit stupid: by purchasing such tasty food you are stimulating the industry to continue production at current levels."

Produced meat is inherently carbon positive, as is all human activity beyond foraging and living off the land. So a carbon neutral powerplant is ficticious from the start*, and "carbon neutral" is a con (a good and necessary one though).

So onto the extension of my little rant on the website:

3M tonnes of wood from abroad?! How is that carbon neutral? A felled tree that is burned, and an identically sized tree allowed to grow in its place is carbon neutral over the growing period of the wood...
Transporting this 3M tonnes (the UK could supply 1M tonnes per year from logging residues alone) of fuel across 3000 miles of ocean when there's the annual 27 million tonnes of landfill we produce sitting just down the road, and this waste already has transport infrastructure for it.

If used as fuel our landfill waste is roughly a realistic potential 2.7% of the UK total energy demand. That's FROM WASTE. You'll need 3 of these Port talbot sized plants to burn it all, the fuel is free, and you solve the landfill problem aswell. The emissions are the same as a normal power plant by the time the gas leaves the chimney, so why not?
Additionally the new plant has an electrical efficiency of 23%... 30% should be comfortably achieveable at this scale; what the hell are Prenergy Power Ltd doing with it?

Thanks for reading! Comments appreciated
Next post - microgeneration and why (I think) its awesome.
Timmy

* unless you produce fusion reactors fuelled by carbon that can fuse enough carbon to offset its initial build, etc... but that's just silly. Awesome, but silly.

Calcs
(links later, googling works though ;D )

Energy from waste
Energy content of landfill waste = 11GJ/tonne
Assumed 50% landfill not suitable (metal, fast decomposition, liquids, non-combustible)
Assumed 25% efficiency of plants (close to that of the new one)
3.375x10^6 *11x10^9 = 37.125x10^15 J
37.125x10^15 /(seconds in an hour x1000) = 10x10^9 kWh annually(10 thousand million units of electricity)
total uk annual consumption = 3.6x10^11 =360x10^9 kWh
(10x10^9)/(360x10^9) = 2.7% (ish) of the nations power from waste.

number of port talbots to deal with waste
27/2 M tonnes/3m Tonnes = 3ish

New plant efficiency
energy content of wood = 16GJ/tonne
3x10^6 * 16 x 10^9 = 48x10^15 J
(48x10^15)/(seconds in a year) = 1.52x10^9 Watts (total energy put into plant in form of wood)
output/input = efficiency
(350x10^6)/(1.52x10^9) = 23% ish

recipe for disaster...

Here's the list. Guess what i'm making.

3x 625g tins of rice pudding
2x small tins sweetcorn
2x value treacle sponges (in tins)
2x tins chopped tomatoes
1x can value grapfruit segments
(pic to follow)
No, its not a weird dessert for 15 people. It's my (Elliot's really, he'll be paying for it in the long run) jet engine.

Basically, sheet metal is a bitch to buy and form into tubes considering the closest I have to a (arc) welding kit is rusted solid and erratic enough to either not melt the stick or to melt through 3mm of metal at first contact, leaving a decent sized hole complete with flying chunks of molten metal. Welding anything as thin as the 1mm sheet steel I'd be using would be like trying to cut paper neatly with a schitzophrenic chainsaw.

My solution is to rivet and crimp and hose/jubilee clip (you know, the metal version of cable ties you do up with a screwdriver) the preformed cylinders into something vaguely resembling the pulse jet design I mentioned earlier. Like this. (pic to follow) The choice of cans was based on size and whether they would stack properly. And on whether I'd actually eat the contents; so much for my diet. i'll get some eating in and hopefully you'll see something kinda like a jet engine by this time on tuesday next week.

Beyond the problem of materials is getting a vapourised/nebulised/gaseous propellant into the engine. I'm either going to use BBQ/camping bottled gas as it comes with loads of safety features already fitted, or R/C car petrol which is badassly flammable and easily dispersed using a spraypaint gun. The ignition is one of those long kitchen lighters which will simply be wedged into the chamber, or a spark plug, whichever is cheaper/easier.

My lunch is over now, so anyone whose lunch isn't over (or is really bloody bored) go look up how to X-ref in autocad LT 2007 without it f***ing the f***ing hell up. And then tell me! Or just provide me with a bucket of patience and one of those stress relief squidgy shapes.

Peas out!