The biomass furphy

 From Just Have a Think

Two quotes:

The legal mandate to record forest biomass-fired energy as contributing to the EU's renewable energy targets has had the perverse effect of creating a demand for trees to be felled in Europe or elsewhere in order to burn them for energy, thus releasing the carbon into the atmosphere which would otherwise stay locked up in the forest, and simultaneously drastically reducing the carbon sink strength of the forest ecosystems;

and: 

The scale of this operation is astounding, with a year's worth of [wood] pellets consumed by Drax representing wood mass approximately equivalent to clearcutting a forested square extending to 18 miles [29 kilometres] on each side.

So, here's what we do.  We give subsidies to companies that plant trees, because negative emissions, and then we give subsidies companies that burn the wood to produce electricity, because carbon-neutral.  Dotty.

De-carbonising electricity generation

1. We'll need both wind and solar, plus hydro, tidal, small hydro, and wave power, and any legacy nuclear.   The reason we'll need both wind and solar is that the wind blows at night, when the sun isn't shining, and also that they are negatively correlated.  In summer in high latitudes, the wind drops off, but solar is surprisingly strong.  In winter, the sun in high latitudes is dim, but the winds tend to be strong.  Together, wind and solar can produce much less variable output than either on its own, except in the tropics.
2. We'll need 4 hours of storage.  4 hours will be enough to handle the morning and evening peaks in demand, and to do some short-term smoothing of the random fluctuations in wind, though geographically diversified wind farms will help with this.  But 4 hours will not be enough to take wind and solar to more than 90% of total generation.  We'll need long-term storage for that.
3. We'll have built-in generation overcapacity.  Remember, that wind and solar variability can mean not just too little generation but also too much.  Up to now, when it's potentially too much, the grid operators curtail output of wind and commercial solar farms.  They're also getting the ability to curtail output of rooftop solar too, in many locations.  In future, this output will not be lost but used to generate green hydrogen.
4.  Storing hydrogen is hard.  Its atoms are very small and easily escape through the interstices between larger atoms, meaning the using hydrogen for seasonal storage will be much less effective than using methane.  It also makes pipelines brittle.  Green methane can be made from hydrogen using the Sabatier method, with a small additional loss of energy.  Methane is already routinely stored for months with minimal losses; there are already methane (natural gas) grids in most mid- to high-latitude developed countries, where seasonal storage will be needed; gas peaking plants will not need to be retro-fitted to handle hydrogen; methane is much easier to store and transport than hydrogen; and it can be used for heating, though electric heat pumps may be cheaper and more efficient.
5. It's possible, though I am not convinced, that we will need some small percentage (10- 20%) of nuclear in the grid.  But we are a long way from 80% wind and solar penetration in most global grids--the most recent data have the global average at 10%.  Setting aside legacy nuclear, new nuclear, if it happens, will tend to be smaller plants, because the giants are just so expensive.  I've talked about SMRs, micro nuclear and the great potential for hydrogen-boron fusion reactors, but these are all at least 5 to 10 years away from them being successfully deployed.
6. Micro-hydro, tidal power, wave power and electricity generated from incinerating/gasifying rubbish will all be handy additions to the grid, because they  are uncorrelated with wind and solar.  Even waves, which are driven by wind, can be created by winds hundreds of kilometres away.

OK, how does the actual transition happen?

1. We could leave it to the market.  Wind and solar are much cheaper than new coal and gas, and comparable to existing coal and gas in most places on the globe.  As existing fossil fuel power stations age, they will be replaced by renewables plus storage.  This will take decades, however, so, since we want to substantially reduce emissions from power generations as quickly as possible, we'll need to give this process a nudge.
2. We could set targets for renewables.  Each utility/electricity producer will be required to achieve an annual/quarterly percentage from renewables, rising steadily over time, aiming for 100% within a decade.   Those utilities which exceed this target will earn carbon credits, those utilities which don't reach this target will have to buy credits.  This carbon penalty will encourage utilities to build out more wind and solar farms, as well as other renewable supply, including nuclear.
3. We could run a reverse auction where individual power stations would offer to close down for a fee.  Let's say a decline of 10% a year in emissions from electricity generation is required.  Each year, the government would offer a lump sum payment to the power stations which would close down, choosing those with the lowest offers until the total reaches 10% for that year.  Conditions could be applied to any deals: redundancy payments to workers; requiring the output of the power station to be replaced with new "firmed" output from renewables; making sure the new wind and solar farms are located close to the communities where coal power stations are ceasing to operate.

Source: Our World in Data

Danish island ends fossil fuel use

Bleak and windswept Samsø generates all its own electricity. Image: By Kyrre Havik Eriksen on Unsplash

It can be done.

Tackling climate change is urgent. It’s too urgent to be feasible, say some critics. But as one Danish island ends fossil fuel use, its story shows it  may be time to think again.

In five years, by 2023, the UK Met Office says, global warming could temporarily [?] rise by more than 1.5°C above pre-industrial levels, the target agreed by 195 governments in 2015. So the world needs to switch fast from fossil fuels to renewable energy.

The island of Samsø, off Denmark’s east coast, has wasted no time. Between 1998 and 2007 it abandoned its total dependence on imported fossil fuels and now relies entirely on renewables, mainly wind and biomass. It’s been singled out as the world’s first 100% renewable island by the Rapid Transition Alliance (RTA), which says Samsø can teach the world some vital lessons about changing fast and radically.

In 1997 Samsø, with 4,000 inhabitants, entered a Danish government competition to develop a model renewable energy community, aiming to prove that the country’s target of reducing carbon emissions by 21% was achievable.

Samsø’s winning proposal was based on strong community engagement and a cooperative ownership strategy. It showed how to make renewables a social, economic and energy success.

What the islanders did was straightforward enough. By the year 2000 they had installed 11 wind turbines, covering their electricity needs. A further 10 offshore turbines were erected in 2002, generating enough energy to offset emissions from their cars, buses, tractors and the ferry to the mainland. Three-quarters of their heating and hot water now comes from biomass boilers fuelled with locally grown straw.

Samsø’s transition, the Alliance says, proved that a wholesale shift to renewable energy was possible with existing technology and limited government assistance.

Nowadays, residents are producing so much more clean energy than they need (and exporting what they don’t use) that, in effect, they have an average annual CO2 footprint of minus 12 tonnes per person, helping their fellow citizens to lower their emissions too (the average Dane emits 6.2 tonnes of CO2 a year, the average Briton 10 tonnes)[US 19.9 tonnes, Australia 25 tonnes].

Samsø, the argument runs, proves the effectiveness of setting ambitious targets – and meeting them. The Alliance says Samsø’s transition is impressive because it was achieved with the active buy-in (both figuratively and financially) of the local community.

Winning hearts and minds was crucial. People often oppose on-shore wind turbines as a visual intrusion, a blot on the landscape. So the transition organisers, Samsø Energy Academy, worked out how to include the islanders as the turbines’ owners.

They had a simple principle: if you could see a turbine from your window, you could sign on as a co-investor, meaning that anyone living with the technology had a stake in it and stood to.benefit

With so many islanders having a direct stake in the turbines there is now near unanimity that the renewable transition has been good for Samsø. Of the 11 onshore turbines, nine are owned privately by local farmers and two by local cooperatives. Five of the offshore turbines are owned by the municipality, three privately and two cooperatively by small shareholders.

Before the transition began Samsø had relied mainly on oil, with its electricity generated in coal-fired power plants on the mainland. The potential for renewables had not been explored, and there was deep scepticism towards them. A lack of opportunities for education and work had led many young people to leave the island.

The islanders embraced the transition, but not because of climate change. Instead, most looked to its potential to provide jobs, strengthen the local economy and secure greater energy independence.

Key to Samsø’s success, the Alliance believes, was the insistence on transparency, consultation, and starting from what people wanted. From the start there was full disclosure of information, with the master plan published in the island’s library and information shared through the local newspaper and discussed in detail at regular community meetings.

Samsø’s long tradition of agricultural cooperatives also helped to ensure strong local engagement. There was ample time for discussion and decision-making, which helped to build confidence and a strong sense of collective ownership of decisions.

[Read more here]

Samsø beach (Source Visit Samsø)

Waste to energy plant

Electricity generated from biomass has a part to play in our energy transition.  A small part, but still useful.

From Melbourne's The Age newspaper:

Melbourne’s western suburbs, which have long been blighted by stinking rubbish tips, could be the site of a waste to energy plant that would convert household waste into enough electricity to power up to 20,000 houses.

The $100 million plant, proposed for Laverton North, would take up to 200,000 tonnes a year of residual household waste which is currently sent to landfill. This is the equivalent of household waste from three to four councils.

Using a process known as gasification the waste would be heated at a very high temperature where air is limited to ensure it doesn't burn. The waste is converted into a gas that is then used to heat water into steam and drive a turbine to produce electricity.

Thermal waste to energy technologies such as gasification and incineration – where rubbish is burned – are common methods of rubbish disposal in Europe, Asia and the Middle East.

However Australia has been slow to embrace them, in part due to the cheap cost of landfill.

Last year Western Metropolitan MP Cesar Melhem undertook consultation on the opportunity for waste to energy in Melbourne’s west.

“People want to see an end to landfill – the odour, rubbish flying all over the place. Houses are encroaching on landfill,” he said.

His consultation found there was broad support for waste to energy in Melbourne, although the community had concerns about how the technology worked, what risks it might lead to and how hazardous byproducts such as fly ash would be handled.

Mr Melhem said that in this day and age anything that created methane, such as organic and food , should be banned from landfill.

“I think waste to energy is an absolutely great way to go about handling residual waste into the future,” he said.

“All the experts are telling me that if you use the European standards, emissions are lower than landfill and we can generate electricity.”

[Read more here]

This plant would use just a small proportion of the rubbish greater Melbourne produces each year.  I estimate we could produce 5% -10% of our electricity from similar waste-to-energy plants, or almost as much as we get from hydro power.

Source: The Age