Co-firing and the renewables obligation

Carbon capture and storage is interesting, yes, but the co-firing of biomass is what particularly interests me, what get's me out of bed in the morning.

So when I stumbled across the government's response to the latest consultation regarding banding of the renewables obligation I thought that I would give it a read.

It contains confirmation of what I thought I knew, which is nice.

The Renewables Obligation (RO) requires electrical supply companies to sell to their customers (that's you, me, and our employers) a minimum percentage of "renewable" electricity. Handily the RO tells you how you can do this with a big long list. I won't bore you, but it contains all you'd expect - wind, wave, solar, geothermal and of course co-firing of biomass.

Now originally co-firing of biomass (with either coal or gas) was due to be written out of the renewables obligation from 2016. Madness. This has now changed so that it will be supported, possibly until 2037 (although with so many recent policy changes it may not last all that time).

There was also a cap put on the system - so that co-firing could not be used by a supplier for more than 10% of their obligation - meaning they had to invest in wind and wave for the remaining 90%.
This makes sense, it stabilises the RO.
This cap has been raised to 12.5% of the suppliers obligation - so whilst wind, wave (etc.) can be used to make up 100% of the suppliers obligation (if the suppliers wish it), wind and wave have to make up at least 87.5% of the electrical mix.

This has all now changed.

The government has realised that different technologies cost different amounts of money (offshore wind is more expensive than onshore wind!). From the spring (or whenever parliament enacts the legislation) different technologies will receive different levels of support.
The co-firing of regular biomass (agricultural waste) will be halved in value - so twice as much will have to be burnt for the same level of support.
Burning energy crops in dedicated plants (so not with coal or gas) will be worth twice as much - so half the electricity can be generated in this manner for the same level of support.

This is why so many new dedicated biomass plants have recently been announced.

On the whole this will reduce the support paid to coal fired power stations - or encourage them to burn more and more biomass.

Time will tell.

Another dedicated biomass power station

I'm starting to loose count of the number of biomass stations which are either being proposed or built - especially recently.

The latest offereing from RWE will be for a 75MW unit. Still pretty small on the scale of thing things - the size of a couple of wind farms.

There is a good reason why so many new dedicated biomass power stations are being built at the moment - the government is changing the way in which renewable obligation certificates are distributed in April. This will mean that biomass burnt on its own will be worth three times the amount of biomass burnt with coal.
Of course the cost will be substantially more as well!

This is probably a step in the right dirrection. Excellent.

Carbon Capture Ready consultation

I was asked to put together a response to question 15 of the governments CCS consultation.

Here's what I wrote - it's not exactly brief.

What might be the impact of the potential costs of CCR [carbon capture ready] for 100% biomass power plants and so the implications for their future build? Should the Government explore excluding 100% Biomass schemes from the proposed Article 32?

The implication of a CCR requirement is that the plant will, one day, be required to fit CCS technology.
As a fuel biomass contains more hydrogen and oxygen than coal – meaning that it contains much less carbon (perhaps only 45% for Switchgrass whereas a bituminous coal may contain 85% carbon). Equally the calorific value of biomass is normally lower than that for coal. BCURA report a calorific value of approx 34 Mj/Kg for Pittsburgh No. 8 (daf basis), whilst Bridgeman et al (2007) report a value of around 17 Mj/kg for switchgrass.
This suggests that the flue gas coming from a 100% biomass plant is likely (on a constant energy out basis) to not only be of substantially greater volume (perhaps twice the volume) but also to be of lower CO2 intensity. Both these factors will combine to make CCS with amines more difficult and expensive.
As such it is likely that the cost associated with any CCS (and therefore by extension CCR) requirement for 100% biomass plants would be – when compared against the cost of the plant – greater for a biomass plant than for a coal fired plant.

This suggests that power generation companies may choose to spend their capital by investing in co-firing facilities (where the small biomass component will have a marginal effect on the CO2 stream) rather than dedicated biomass plants.
This decision will of course be influenced by many other parameters (including the RO) upon which I don’t feel qualified to comment.

I know of 5 reasonably sized proposed / existing 100% biomass plants in the UK. Lockerbie (44MW, Eon), Ely (38MW, EPR), Sheffield (Proposed 25MW, Eon), Bristol (Proposed 150MW, Eon), Port Talbot (Consented / Under construction 350MW, Prenergy Power).
I would suggest that to date there is no conclusive evidence as to the optimum size of a 100% biomass power station (largely it depends on what fuel can be made to be available). As such any requirement for 100% biomass plants to be CCR (and by extension for future CCS) may have the effect of limiting the size of such plants to sub 300MW.
As such it is probably desirable for the government to investigate excluding 100% biomass plants from the mandatory CCR requirement.

This assumes that 100% biomass plants continue to be seen as carbon neutral whereas they should probably be seen as low carbon (especially the Port Talbot and Bristol 100% biomass plants which may emit large quantities of green house gasses in the transport of their fuel from North America).

Biomass in Bristol

Eon have just announced that they intend to build a 150MW power station in bristol - powered by biomass.

The fuel for this station, much like the one proposed for Port Talbot, will probably come from places such as Canada, or perhaps Scandinavia.

The proposed bristol plant is pretty small - using 1.2 million tonnes of fuel year. That's still such a large amount that you wouldn't consider shipping the fuel in by road - so the vast bulk of it is going to have to come in by ship.
This is the problem with such stations - fueling them is very difficult. Coal moves from a point source (mine) to a point source (power station), whilst wood moves from a distributed source (many different forrests, one cannot provide enough fuel) to a point source (power station).
I don't want to argue that coal is more sustainable than biomass, but it does have the advantage that it doesn't tend to move around the country quite as much - creating less noise polution and generally not getting in peoples way as they try to get to work.
That's got to be seen as a benefit.

Interestingly I've also just noticed a protest site for the Port Talbot development. Largely their concerns are baseless - for example they are trying to smear the development by refering to Chenobyl, and complaining about an extra 17 HGV's a day leaving from a large industrial estate and docks complex.
Rather this is a classic case of NIMBY (not in my backyard!), where people with access to the internet, and who don't really understand what they're talking about, can try and sway the general population.

The difference between that and this blog?
I understand what I'm talking about.

As expected

It sounds like the kingsnorth climate camp is going to turn into a climate village - the protesters are talking about not leaving.

I think that's harsh on the farmer who's land they've taken.

They'll laugh at me and say "bigger issues exist" and wheel out their scientists to say that they're right.

Here's the thing - I've just noticed that their scientists say that their wrong.
Takes James Hansen - NASA guy who knows about global warming.
He's been advocating biomass and CCS as a method of generating power and taking carbon out of the atmosphere.

He knows that you need to big source of carbon to make the CCS (and hence carbon negative electricity) efficient - i.e. a coal fired power station co-firing biomass, right?
Provided (e.g.) 11% of the carbon going into the boiler is from the biomass whilst (e.g.) 90% of the carbon dioxide is captured from the boiler you generate carbon negative electricity.

Blackburn Meadows

Eon have just announced that they have secured planning permission for a dedicated biomass plant in Blackburn Meadows, Sheffield.

It's tiny though - only 25MW. By comparison a coal fired power station would be up to 1500MW.

I can't help but feel that building small dedicated biomass plants is not the best way ahead.
By co-firing biomass it's possible to burn more biomass at higher efficiency - for example one unit at ferrybridge power station has 6 25MW gasifiers bolted onto the back of the boiler which, after leveling to electricity is equivelant to, perhaps, 60MW.

Burning biomass in larger boilers is more efficient - and with a projected global fuel shortage efficiency matters.