Tim- Thanks for the posting, it is very interesting when you compare it with the previous reasons given for subsidising the production of dedicated biomass in the UK.
Previous statements claimed that this biomass production would stabilise UK energy costs but the BBC programme detailed a doubling of miscanthus price plus it confirmed the intention to import 79 million tonnes of biomass/yr thousands of miles. This ignores GHG impact, energy required to dry and pelletise timber plus health and environmental costs resulting from degradation of air quality caused by biomass combustion.
I note UK miscanthus/ straw burning plant operators claim fuel will be sourced within 50 km radius of the plant but the programme reported from a Shropshire farm supplying Ely power station, the Ely power plant representative confirmed they source from Staffordshire. Miscanthus is low energy density which creates substantial transport impact.
The farmer claimed use of marginal land for miscanthus production but confirmed using all the farm. Farmers are being heavily subsidised to transfer from food crops including wheat to dedicated biomass production but this ignores the increasing need for food and other demands such as the new ethanol plant at Hull requiring 1,100,000 tonnes of wheat each year.
Where is the due diligence in UK combustion energy policy ?

Posted By: BrianwilsonThe farmer claimed use of marginal land for miscanthus production but confirmed using all the farm.

I think I recall a phrase something like "good deep loam" being mentioned for for the initial seed plantings at least.

It was more or less tacitly accepted in another (think it was the 'fuel for the 21st century') thread that the definition of "marginal" would gradually be expanded to mean "more or less marginally profitable" as biomass feedstocks assumed a greater importance as an alternative to FF, the truly marginal (in terms of productivity for food) acreages having proved inadequate to feed a growing market. And as fuel has always attracted a premium, the scarcer the product the better price it attracts and the more attractive it becomes. For a business in the business to make profit and faced with the choice: Food or fuel? It's a no-brainer.

Here here

<blockquote><cite>Posted By: DamonHD</cite>One of the best current-technology solar energy systems we have on the scale required *is* biomass, for the UK.

Rgds

Damon</blockquote>

How do you reach that conclusion?

The very best, most efficient biomass crops struggle to get better than around 6 to 8 % energy conversion ratio, yet existing PV manages double that with ease. This means that biomass crops require more than double the land area for a given energy output than PV would require, a point already made somewhere in the depth of the bimass thread.

The only advantage that biomass has is easy storage, but that's offset to some degree by the energy that needs to be expended in preparing the stuff for use as fuel, that used in transporting it to where it's needed and in the treatment and removal of the waste products once energy has been extracted from it.

Reference storage of biomass, with regard to straw we know 25% can be rendered unsuitable for purpose during storage and 12% lost due to arson. Woodchip comes with storage problems, spores ,self ignition etc. Pellets , ingress of moisture?
I note a small biomass power proposal on a Scottish Island will burn green timber straight from a good store, the forest , water content estimate over 50% , sadly PM creation will be 200g plus per Gj of energy in equating to exhaust emissions from 39 million diesel vehicle km /day, process efficiency obviously poor but fuel is cheap. Where is the due diligence and duty of care when aware of clean alternatives?
Dave is correct money appears to motivate actions in all aspects of energy provision but who pays the price, people like Mikee sadly

<blockquote><cite>Posted By: Ed Davies</cite><blockquote><cite>Posted By: SteamyTea</cite>True it can be stored, but so can electricity, ..., just lift a weight up high and then let it fall when needed.</blockquote>
Really? In a gravitational field of 10 N/kg (i.e., a field causing an acceleration of 10 m/s², slightly more than Earth's) lifting a mass of 1 kg through 1 metre stores 10 J. 1 kWh is 3600 kJ so to store 1 kWh you'd need to lift 1 kg though 360 km or 1 tonne through 360 metres. I applaud your imaginative use of the word 'just'.</blockquote>

Works OK for pumped storage stations, like Dinorwig. Not high efficiency, but certainly workable and a way of making use of periods when generation exceeds demand.

Just checked the figures, it's actually not as bad as I thought. Input power is 275 MW for 7 hours (so 1925 MWh), output power is 288 MW for 5 hours (so 1440 MWh). Looks like it runs at just under 75% efficiency as an electrical energy store, which isn't bad at all when compared with other technologies around.

JSH: "The only advantage that biomass has is easy storage" is *the* prime advantage to store the scale of energy required for GB to ride out one of DECC's 5-cold-windless-days scenarios. I know that the conversion ratio of biomass cf PV is horrible (which is why I am a fan of PV), but there is simply no electricity storage on a similar scale available to us yet, other than flooding much of Scotland and Wales and the Lake District, which I think would be even more unpopular than (properly) burnt biomass.

rgds

Damon

Posted By: DamonHDflooding much of Scotland and Wales and the Lake District, which I think would be even more unpopular than (properly) burnt biomass.

How about France

Using that 75% efficiency figure for pumped storage and my daily winter usage of up to 30 kWh and Eds figures of 1 tonnes lifted 360 m per kWh and if I swapped the water for iron at about 7 tonnes/m^3 and limited the lift to 6 m, then:

Mass would be 5250 tonne, which would be 750 cubic meters lifted 6 m. Could 'just' about fit that in my back garden.

You wouldn't see it for all the other stuff he's got piled there.

Rather than steel, maybe the answer is to use some of that waste depleted uranium we have stockpiled. It'd only take up about 40% of the volume of steel for the same stored energy..................

Posted By: DamonHDdigging itself a hole and vanishing?

Where I thought of putting it, then covering it over with the earth

Can't really be 5 kt can it to store 30 kWh

Posted By: DamonHDIt's no wonder that fossil fuels are so attractive.

Petroleum is just a fantastic product, and you can get if from drilling a small hole in the ground as well.

I suspect that storage will be a mix of technologies, just like generation, so no one technology will be a 'one size fits all'.
Will come down to:

Pumped Storage (other gravity methods)
Flywheel
Battery
Hydrogen
Compressed Air/gas
Temperature (hot and cold)
Super Capacitors