We are a lucky generation – we're living at the dynamic beginning of massive global transformation. It's a time to ask big things of ourselves and of each other – just as Winston Churchill did in a speech to the British people at the beginning of WWII.
We are in the preliminary stage of one of the greatest battles in history. ... I have nothing to offer but blood, toil, tears and sweat.
Winston Churchill
This is the decade when Australia needs to make a serious start on a national plan to shift electricity generation from 8% renewables to 100% renewables.
Beyond Zero Emissions, a climate policy think tank, has produced a roadmap that shows how Australia can do this over just 10 years, at a cost of 3% of GDP. The Zero Carbon Australia plan involves approximately 6,400 wind generators (7.5 MW capacity) and nearly 200 Concentrated Solar Thermal (CST) plants spread across Australia's best solar and wind regions. Here's how it looks.
The new CST plants and wind farms would be built in clusters and joined to the national grid that will be enhanced with additional HVAC lines as well as some HVDC lines for longer distances. HVDC power lines lose only 3% of power per 1,000 km.
The focus on two technologies, CST and onshore wind turbines, is a result of several factors.
- CST and wind turbines are commercial off-the-shelf technologies so there is no delay in getting started.
- Australia has excellent solar and wind resources (e.g. we have plenty of room for onshore wind turbines so we don't need any of the more expensive offshore wind farms).
- Together, CST and wind can deliver reliable baseload power that is sufficiently flexible to dispatch power at short notice and cope with variability of demand and changing weather conditions. CST with salt storage delivers electricity 24 hours a day because the molten salt stores heat from the sun to keep the turbines turning through the night.
Australia is not alone in planning continent-wide electricity grids that rely on renewables. Desertec has done similar planning for a grid that encompasses Europe, North Africa and the Middle East. Like Australia, deployment is at an embryonic stage. A CST plant has been commissioned in Tunisia while Saudi Arabia and UAE are rolling out ambitious programs for utility scale solar power. They are positioning themselves for the post-oil era so they can continue to be energy exporters.
In the US, the National Renewable Energy Laboratory (NREL) report Renewable Electricity Futures Study (RE Futures) demonstrates that the US (lower 48 states) could be 80% renewable by 2050.
The Australian government is comissioning its own study to show how Australia's electricity could transition to 100% renewables by 2030 or 2050.
So now the thought has been thought, it's hard to unthink it. We are at the beginning of an energy revolution. The transition to 100% renewables will be a battle, tooth and nail, with wealthy and powerful fossil fuel interests. They will oppose every step that reduces markets for their coal, oil and gas.
Churchill was lucky, the European theatre of war in WWII lasted only five years. In contrast, our battle with fossil fuel interests will last for decades. It will take toil, tears and sweat, and even blood. Plenty of blood has been spilt defending oil resources, and it is likely to happen again.
That's why I say we are a lucky generation. We live in times that ask a lot of us. Can we rise to the challenge?
Don't ask little of me, you might get it.
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The Transformation tab reports examples of progress towards a low-carbon future. Here are recent snippets.
Morocco, Saudi Arabia, UAE and South Africa are building utility-scale solar generators using Concentrated Solar Thermal technology. Source: ConstructionWeek.
Morocco maintains a national renewable energy and energy efficiency strategy that includes renewable energy sources meeting 42% of electricity demand by 2020. Source: Cleantechnica.
I have a little bit of a problem with this bit:
ReplyDelete"Together, CST and wind can deliver reliable baseload power that is sufficiently flexible to dispatch power at short notice and cope with variability of demand and changing weather conditions."
I'm always on your side of this argument. I don't believe that baseload generators are necessary and I'm certain that 80% or 90% of Australia's total power demand may, eventually, be sourced directly from the sun and the wind using the technologies mentioned. It is reasonable to credit wind with being "reliable baseload equivalent" when, by spreading wind generators widely enough across a continent, there is a specific power level above which wind will reliably generate for 90% of the time -- since no fossil-fuel or nuclear baseload power station can guarantee better than 90% capacity factor or no unscheduled downtime. Of course if you build that much wind capacity, most of the time it will be generating rather more, so if you install enough to guarantee most of your "baseload" demand you'll have surplus power for much of the time.
But you can't describe either technology as "flexible to dispatch power at short notice" -- rather, they're generally very predictable. You do know several days in advance when there will be widespread calm or cloud. (You also can't really describe concentrating solar thermal heat storage electricity as "off the shelf" ... it's an emerging technology, very new).
In the case of heat storage I suppose you can indeed dispatch it until the heat store is depleted -- though in practice I expect the solar collectors and turbines will be scaled such that there's little excess to store over what is used during the day. BZE's charts show overnight generation depleting the thermal store steadily overnight but only from 80% down to 70% of the total storage available -- in other words they expect to have storage capacity of solar heat sufficient to generate full power for up to ten days from a full charge. Solar collectors and the storage are expensive; turbines are indeed off-the-shelf and relatively cheap, so any early developers would maximise daytime power before spending big on surplus collectors, tanks and insulation in anticipation of a cloudy week that happens once or twice a year. As long as fossil fuels are still in use, storage of solar heat will for economic reasons mostly be used to cover evening demand peaks in the few hours after sunset. Since the heat store can be charged only by direct sunlight (or combustion of fuel delivered to the site) it is quite vulnerable to periods of overcast.
Hi Jonathon,
DeleteYes, this post gives a very broad brush view of the BZE proposal. From what I understand, the mix of CST and wind that is proposed is more economic than achieving full coverage with wind alone.
I'm comfortable calling CST dispatchable because I expect that there would be sufficient capacity (or over capacity) to cover a large proportion of unusual demands. The graphs on pages 80-81 show the modelling for how the proposed mix of wind, CST, and some hydro/biomass, would meet expected demand. I'm sure that this isn't definitive and there will be a lot of ongoing modelling of various supply/demand scenarios as we make the transition.
The issue of whether CST and wind, together, should be called 'dispatchable' or 'predictable' seems like a fine point that depends on how the grid is run. Both terms need to come into the discussion for those people who have a fairly simple view that coal generators run 24/7 delivering a steady flow of electricity. As you know, all power stations work at less than 100% capacity and grids need to cope with fluctuations in supply.
As you say, "as long as fossil fuels are still in use" they'll be used to provide capacity. The BZE plan is very ambitious in aiming at 100% renewables. Strategically, it's a good position to take because if it shows that the most ambitious target is possible, it also supports less ambitious targets.
The campaign and proposal I read from the BZE people ( http://media.beyondzeroemissions.org/ZCA2020_Stationary_Energy_Report_v1.pdf ) actually proposes using wheat chaff on site in place of sunlight for "contingency" to cover 2% of annual electric demand in periods when the heat storage runs out and there's but a feeble breeze. That 2% figure reflects highly optimistic assumptions about CST heat storage : 5% to 15% is more realistic. Crop residue is indeed renewable, and I suppose it's technically feasible to do this, but it seems to me prohibitive (in transport costs alone) to establish a new industry to collect and distribute and generate power from crop residues, whether for 2% or 10% of annual electric demand.
ReplyDeleteGiven that an enormous fossil fuel based electricity industry with immense capital already exists; given a biogas industry (heavily in development in Europe, if not here) that readily integrates with the fossil gas infrastructure; given the potential to expand existing electric power storage techniques such as pumped hydro; and given rapid technological development worldwide of numerous new ways to store excess electricity for a still, cloudy day, I doubt very much that we will see either storage of solar heat for periods of weeks *or* the "co-fired wheat chaff". Crop residue is, at best, a minor on-farm fuel or feedstock for biogas.
We must push for ever-deeper integration of intermittent renewables into the existing electric power system while phasing out the dirtiest fossil fuel burning components. In the short term this means brown coal (though to date it's black coal, as an expensive globally traded commodity, that gets pushed out through market merit order) but ultimately of course it means fossil gas as well.
Only when all the coal-fired power stations are retired does it make sense to worry about whether the remaining fuel used to bridge the still, cloudy days (as little as 10% or 15% of total demand in Australia) is fossil or renewable.
Hi Jonathon... yes, I didn't mention the 2% biomass because the post was more general.
DeleteI see where you're coming from re the plan to use biomass. I'm not sure of the details, but I don't dismiss the biomass suggestion. NSW's ethanol is produced from biomass and all sugar mills generate bagasse that is used to produce electricity and could be ramped up further. Waste transfer stations in Sydney send biomass to Hunter Valley coal generators. So we already have the basis for a biomass industry.
You probably know that I really like the idea of pumped hydro, so I expect that we would see some of that at some stage. Also, as the vehicle sector is electrified, there are those potentials for car batteries to act as a back up. The BZE plan was written two years ago, and was based on the premise of a fast implementation (across 10 years) so it works within the constraint of existing technology. As you say, by the time we need that kind of backup, it's likely that other solutions will be more practical.
I agree with you that the transition of electricity to 100% renewables is likely to be phased over several decades and all kinds of things will come into play along the way.
The most important value of the BZE plan was that it got the ball rolling and demonstrated that there is a viable version of 100% renewable electricity. The govt is currently letting a contract to do its own study to demonstrate how Australia's electricity could be 100% renewable by 2030 or 2050.
I do see CST as commercially viable. The Gemasolar plant provides enough power for 25,000 homes - that's five towns the size of Renmark. The Tonopah plant currently under construction in Nevada is three times as big. Currently there are 20+ CST projects underway worldwide with a total 17.54GW capacity. Among others, the Saudis are taking a lead... http://www.constructionweekonline.com/article-17709-saudi-group-close-to-winning-500m-solar-contract/
I read a study somewhere that compared the economics of CST without molten salt compared with the molten salt version. Apparently the molten salt version was 20% more cost effective in the longer term because of the capacity to generate power into the evenings. [Not sure I expressed that accurately, but you get the picture.]
You're up late, and I'm up early!