Tag: nuclear energy

COP 26 and Climate Change Action

Will COP 26 be an echo chamber of plausible responses to the climate crisis or a forum that drives change? Will COP 26 be the moment that stops the increase in global temperature, or will it be drowned in politics?

Methane at COP 26

Since 1950 atmospheric methane (CH4) has grown from 1220 ppb to 1870 ppb. On its own, it has increased temperature during that period by 0.13C. Breaking up this increase by its components reveals the following:

  • 57% from fugitive emissions from natural gas.
  • 25% from ruminant animals (both farmed and wild).
  • 13% from waste.
  • 9% from fugitive emissions from coal.
  • 6% from rice cultivation.
  • 6% from biomass.

Most of attention in regard to methane emissions has been given to belching from ruminant animals. Yet cutting red meat (and rice) from our diet is not a matter for COP 26, IMO. Yet there are other matters to be considered at this conference. For example, what about fugitive emissions from natural gas?

Let us suppose that in the next 10 years we were able to cut methane emissions from everything except ruminant animals and rice cultivation by 50%. In this case the atmospheric methane would fall from 1870 ppb to 1730 ppb. This would be just the beginning, for it would continue to fall out to 2100. In other words, instead of contributing to the growth in global average temperature, it would mitigate the increases from other sources.

The move from coal to natural gas for electricity generation may have been a good idea at the time, but we should not now chose to use these gases for electricity production. If this is done and also we cut methane emissions from waste as well as changing from biomass to electrical cooking and heating, this would reduce atmospheric methane, without doing anything else. So a cut in methane emissions by 2030 should be on the COP 26 agenda.

Actual and projected increases in global average temperature since Industrialisation.
Effect of cutting methane emissions

F-Gases at COP 26

When the Montreal Protocol was established in 1990, it was realised that moving from ozone-depleting CHCs to other gases would increase atmospheric greenhouse gases. At the time it was agreed that certain gases mentioned in the Montreal Protocol gases would be fazed out from 2025. Yet there is no sense that this commitment is being taken seriously in the run-up to COP 26. It should be included in the final agreement.

Electricity Production: Low CO2

Presently, there are only two viable models for electricity production in a low CO2 environment: nuclear and intermittent sources. While nuclear is favoured in some places. It is not favoured in other places. In any event, it would appear that following this route is very expensive. On the other hand, intermittent sources, by their very nature, are unreliable.

It is true that cyclic fluctuations through the week can be managed through an appropriate level of storage, which could be via pumped-hydro, batteries and other more experimental means of storing electricity. Therefore, it is not cyclic and predictable fluctuation in demand that is preventing the take up of intermittent power supply. The problem is in the unpredictable nature of supply. The thing that is holding back more widespread use of intermittent supply of electricity is the lack of a plan to cover the shortfall in electricity supply when the wind or the sun fail to deliver the quantum of electricity that is required. This is the biggest problem in moving to a more complete dependence upon intermittent / renewable supply of electricity.

For nations that are already industrialised there is a simple solution at hand, even though it cuts across the ideological resistance to coal. Yes, the solution is to use coal-fired generators (and any existing redundant gas-fired generators) to provide back up generating capacity in the case of a failure in supply of electricity from renewable sources. In the short-term, the existing coal and gas-fired generators could be brought on line in the event of a failure of supply. Even with the current configuration, this should happen in less than 20% of the time once the intermittent supply system generally provides 100% of electricity power. This approach will ensure a 80% cut in the CO2 emissions from this source. On the other hand, it does mean that banning coal from the electricity-generation field will not be possible, or even practical (if one really wants to cut CO2 emissions).

In a system that does not use nuclear power, it would appear that a properly designed system will provide all power to consumers from renewables and from storage. Under this system, the storage would be replenished from time to time using coal-fired generators. This would only happen when the storage falls below a level in which the operators believe is too low for a measured guaranteed security of supply. Under this scenario, the coal-fired generators would run flat-out until the storage was replenished.

In a system that uses nuclear power, the power stations could run continuously, replenishing the storage in a balanced manner.

Oil-based fuel

We already know how to cut the usage of oil-based fuels for passenger vehicles and light trucks. The simple solution is for each country to mandate that new vehicles must be fully electric. However, this will bring many problems in its wake. These include a complete replacement of the refueling system and potential massive increases in the prices of raw materials. It would be more sensible to move more slowly.

The ideal solution, hopefully to be discussed at COP 26 is for each nation to move towards mandating hybrid, plug-in hybrids and fully electric vehicles for new vehicles well before 2030. The market can then manage the extra cost for each type of vehicle. Since a simple hybrid is not much more costly than a vehicle with a 100% internal combustion engine, this can be the starting default. Even this will cut the consumption of petrol by about 30-40%, which will lead to a significant reduction in CO2 emissions from this type of vehicle.

Solutions for heavier trucks and buses and ships can be considered at a later period. The end result should be that by 2030 we will have a solution prepared for all oil-based fuels.

Cement and Steel

Solutions are currently being considered for the CO2 generated in these two processes. Time is required to allow feasible and proven solutions to emerge.

Conclusion

Significantly cutting greenhouse gas emissions in this way by 2030, in the areas where we already know how to do it, will avert the climate change crisis, and put us on a path to prevent global warming since industrialisation of more than 1.5C. Early and radical action is required.

Such action should be legacy of COP 26. The question remains, will the representatives have the courage to take the actions that are required? Will the members present be willing to abandon those ambitions that will not lead to that outcome, but will hinder this desirable result.

Baseload power in a renewable environment

Baseload power should be reconsidered in the light of the recent blackouts in Texas. While storage can do much to reduce the frequency of blackouts, storage is limited by the electricity that has been already “stored” in either batteries or via pumped-hydro.

In Texas this week, millions of people were stuck without electricity. There wasn't enough baseload power.
In Texas this week, millions of people were stuck without electricity

The primary role of batteries is to manage the difference between supply and demand for electricity during the day. If the surplus supply is greater than the capacity of the batteries, the surplus can be diverted to pumped-hydro facilities, if available. These can be configured to provide much greater electricity “storage” capacity.

In the event that demand exceeds supply over many successive days, it is possible that both batteries and pumped-hydro dams will be emptied. In this case, blackouts have just been deferred for those initial days and not avoided for the whole period. A baseload power strategy is required to reduce the possibility of a catastrophic failure of electricity supply during an unusual climate event.

How much baseload power is required?

The maximum quantum of baseload power required is the maximum unavoidable demand. This is equal to the maximum demand at any time at day or night less the demand that can be cut off by fiat of the regulator, or by negotiation with business. Things that can be planned to be shut off include:

  • Aluminium and steel works can be put into standby mode provided sufficient warning is provided.
  • Domestic and business use of electricity can be scheduled to be shut down in different suburbs and towns at different towns for a short time in order to reduce the peak load.
  • Certain usages can be banned, depending on the predicted willingness of individual users to comply. For example, cooking the evening meal could be postponed until a later hour or brought forward. In a country like Australia, this would not be welcomed but compliance is likely to be widespread. (For the impact of the 6 pm peak see this analysis done a few years ago for South Australia.)

There will be political price to pay for any requirement to reduce demand for electricity, but there will also be a political price to pay if the cost of more baseload power is more than necessary. It is a matter of balancing costs and risks.

Renewables will still contribute to power in a crisis

It is not possible to guarantee that renewables can supply any level of electricity, but the reasonable probability of renewables being able supply a certain level of power can be calculated. The likelihood of an unusual climate event significantly causing the electrical “storage” system to be exhausted will be reduced wherever there is a wide distribution of renewable energy resources. In Australia, this could encompass all the east coast states plus South Australia. The chance of an unusual climate event having the same impact everywhere is almost zero, but some effect can always be expected.

In calculating the quantum of power that can be sourced from renewables in an extended climate-change crisis one must realistically consider impact of such an event if it happened and consider the probability of such an event, say in the next thirty years. This is a matter for engineers and statisticians to consider.

These calculations will not be easy, but they can be done. Once completed, a reduced maximum quantum of baseload power outside the renewable sector can be calculated.

Gas-fired electricity generators can be used

Even though this conflicts with the idea of “net zero” emissions, there can still be a case for at least 10% of the current use of natural gas to be continued into the future while still holding firm to the target that temperature increase since industrialisation are to be held at 1.5C.

The advantage of continuing to use gas-fired electricity generators for peaking electricity demand is that if an unusual climate event happens that leads to electricity supply being curtailed, the peaking-demand generators can be turned on in off-peak times in order to generate electricity to meet the demand and, if possible, to replenish the electricity “storage”.

The electricity that can be supplied by gas-fired electricity in this crisis will also reduce the calculated maximum quantum of baseload power that is required outside of renewable resources.

Meeting the final baseload power requirement

There are three available methods of providing baseload power:

  1. Electricity from biomass.
  2. Electricity from geothermal resources.
  3. Electricity from nuclear power.

The downside of burning biomass is the possible negative environment impact of doing this on a large scale.

Geothermal resources, deep underground, provide an excellent means of providing a constant supply of electricity with virtually no environmental impact (even though a project near the Cooper Basin in South Australia was abandoned because it was not economic at the time). Under the scenario considered here, the electricity produced from geothermal sources could be immediately stored and dispatched as required.

Nuclear energy needs to find a new spot in the world’s electricity network. To do this it will be necessary for its advocates to increase the community’s confidence in the long-term safety of nuclear-powered electricity generation. This could be possible via the smaller modular nuclear molten-salt reactors that are currently being considered.

Final baseload power requirement

Using the Australian National Energy Market as a guide, let us try some rough numbers to calculate a safe capacity:

  • Peak demand capacity: 2019-20: 35,626 MW.
  • Measures to manage demand reduced anticipated peak demand in a climate-related demand crisis by, say, 25%.
  • Geothermal contributes, say, 6% to supply by continuous running = 1318 MW (running 24 hours operation 365 days = 11.55 TWh out of 192.4 TWh).
  • Assume gas-fired peaking capacity (for 1 hour a day) contributes 5% to peak supply to help meet demand = 1,781 MW.

We now move to model total electricity demand per day in a climate-related demand crisis:

  • Total electricity demand in a year = 192.4 TWh
  • Daily electricity demand in a day less 25% = 395,000 MWh
  • Demand that is met by peaking capacity = 1,781 MWh
  • Additional capacity from peaking = 40,963 MWh
  • Daily demand met by geothermal = 31,632 MWh
  • (Normal demand met by wind and solar renewables = 493,000 MWh)
  • Daily demand met by renewables at 25% (assuming storage has been exhausted) = 123,250 MWh
  • Net demand to be met by other baseload capacity = 197,394 MWh.

If the other baseload capacity to meet this situation was able to run 24 hours a day, the installed baseload capacity would need to be 10,000 MW (including a 25% contingency). This represents about 30% of peak demand. If a climate-related crisis is expected to result in increased demand, this will need to be taken into account by providing additional baseload power.

Conclusion

On this indicative numbering, electricity from intermittent sources like wind and solar should, on average, be less than 70% of supply. This can be managed by contracting the above pure baseload generators at a fixed price with a guarantee that these generators will meet the available demand before any intermittent supply is taken up. Unless intermittent sources are subjected to this kind of control, baseload power sources will atrophy and close due to lack of use. Therefore, they will not be available when they are needed.

Of course, these numbers are only an indicative example, with other factors to be included as required, but they do show that 100% renewables could bring problems in its wake.

If the first-call use of baseload capacity is not maintained the whole system is likely to become unstable, leading to serious problems in the supply of electricity to those who desperately need it.