Monday, May 30, 2011

An alternative Long-Term Energy Plan for Ontario - Greenhouse gas-free electricity by 2045

By: Donald Jones, P.Eng., retired nuclear industry engineer.

The present Long-Term Energy Plan (LTEP) for Ontario, from 2010 to 2030, does not look far enough ahead. Instead, Ontario should be asking the question, what should the generation supply mix be after 2045 and what is the roadmap to get to that mix? 2045, and up to 2050, because that's when our 10,000 MW of "to be refurbished" nuclear will be decommissioned and new generation would have to be ready to take its place. Greenhouse gas emissions, possible climate change effect on hydro generation, and the decline in economic reserves of fossil fuels dictate that there must be an increase in nuclear capacity. Nuclear would supply around 80 percent of generation, up from the around 50 percent at present, with hydro supplying the balance. To be completely greenhouse gas-free there would have to be enough nuclear and hydro capacity to meet the maximum instantaneous demands on the system, allowing for any dispatchable demand response loads. This would make Ontario independent of outside jurisdictions, including long costly and unreliable transmission lines, and give it a clean reliable power supply at stable prices well into the future. Until then every effort should be made to reduce the amount of natural gas used for electricity generation to reduce greenhouse gas emissions and conserve it for future generations.

For nuclear to achieve 80 percent of generation would mean that all new nuclear build must be capable of load cycling using changes in reactor power with steam bypass as necessary, and of load following using steam bypass followed up with changes in reactor power. Automatic Generation Control would also be possible using steam bypass. In an ideal world sufficient and suitable demand management loads, thermal storage, hydrogen production, etc., could negate the need for load cycling and load following but nuclear plant design decisions, including those on refurbishment, have to be made now and cannot wait on uncertain future developments. The Ministry of Energy has already made load following a requirement for nuclear new build at Darlington. However, 80 percent nuclear penetration on the grid would mean that the new build nuclear in operation after 2045 (including the proposed 2,000 MW of Darlington new build that will operate for 60 years) would have to have substantially better night time turndown than anything seen up to now in Ontario and would have to use a combination of reactor power reduction together with steam bypass to bring unit output down to around 40 percent of full power.

So, until around 2045-50 the province would have to rely on a generation supply mix of around 50 percent nuclear, 25 percent hydro and 25 percent gas with wind playing interference. The limit of 50 percent on nuclear generation is because, for various technical and financial reasons, the present nuclear plants do not now have the capability to significantly reduce reactor power overnight (required because of surplus baseload generation, SBG, that usually occurs in the spring and fall but is now exacerbated by wind) and then return to full power in the morning within the appropriate time envelope - load cycling. Bruce B has been, and is, called upon to reduce station output when necessary but does this implementing a tightly choreographed procedure of bypassing steam that would normally be used to generate power and not by reducing reactor power. Other Ontario nuclear stations do not power manouuvre, they are either on or off. It is doubtful how long the four units of Bruce B can go on using steam bypass since the original design was that any manoeuvring was to be done by the reactor so the bypass system was not designed for the wear and tear from this kind of frequent use.

The gap between where Ontario is now and where it should be 35 years or so from now could be filled by more nuclear instead of by natural gas if the present 10,000 MW of nuclear slated for refurbishment could be made more flexible. Improving reactor manoeuvrability may not be practical since it is complex and impinges on reactor safety and would depend on the Canadian Nuclear Safety Commission giving it the green light so it may be easier (all relative, nothing is easy) to improve the steam bypass capability of the units so that, at least, load cycling is possible. This would enable the output of the units to be reduced during periods of SBG overnight and weekends without any changes to the reactor power output and enable much more new nuclear to be accommodated on the grid than the 2,000 MW limit in Ontario's LTEP. One of the limits to steam bypass operation is the difference allowed between the temperature of the condenser cooling water coming into the units from the lake and that being discharged back into the lake.

It is the minimum night time output that determines the amount of nuclear that can be accommodated on the grid. The government's LTEP assumes 10,000 MW of refurbished nuclear generation that cannot be turned down overnight and 2,000 MW of new nuclear generation that can. Since Bruce B units have dropped around 300 MW (say a unit power reduction to 62 percent) using steam bypass during overnight periods of SBG there is the potential to add up to 6,000 MW of new flexible nuclear to the grid, on top of the 2,000 MW proposed for Darlington, while still keeping the same minimum overnight output capability. This assumes the 18,000 MW of refurbished and new nuclear can reduce output to an average 62 percent of full power overnight. Doing this would enable a drop in gas-fired capacity from the 9,000 MW or so in the government's LTEP down to 3,000 MW and would help reduce Ontario's dependence on conventional natural gas and on the increasing amounts of controversial shale gas that is offsetting the drop in conventional gas supply. Cost and life-cycle greenhouse gas emissions are concerns with shale gas. Life cycle greenhouse gas emissions may be worse than those from coal and costs are sure to go up as demand increases elsewhere in north America for power generation use and for its many other uses. Reducing the amount of flexible gas generation does mean that less wind energy can be accommodated on the grid.

There is still a lot of life left in the coal-fired units at Nanticoke and Lambton. Indeed they should be kept operating, burning coal, to be available at least through the long nuclear refurbishment program and then gradually replaced with on-site nuclear. Coal generation will be a lot cheaper than gas generation and, being much more flexible than combined cycle gas, it is a better partner for wind if that totally unnecessary energy source is to be continued with. The health risks associated with burning coal at Nanticoke and Lambton have been greatly exaggerated to say the least, to the benefit of the gas industry (just like the hysteria associated with very low doses of radiation) and not to the benefit of the nuclear industry since present nuclear cannot compete with coal on manoeuvrability. Two units at Nanticoke and two at Lambton have flue-gas clean up systems and need not be converted to expensive gas-firing, biomass-firing, or a combination of both. Expensive flue-gas clean up systems are not even necessary on the other coal-fired units since emissions have little health risks, even more so considering the limited use of the units. These assets belong to the people of Ontario and should be kept in operational readiness. If the refurbishment of the 10,000 MW of nuclear does not include the improvements that would make the units more flexible enabling more new nuclear build, then flexible coal-fired units can be used instead to protect Ontarians from gas price hikes over the next 35 to 40 years until new nuclear is on line. Having coal generation available to compete with gas may keep electricity generation costs in check and reduce the large amount of contracted gas generation that has led to the present surplus and the need to export it at subsidized prices.

Since the long term outlook for wind and non-renewable natural gas is bleak the billions of dollars being invested in the so called smart grid should instead be put into improving the reliability of the existing centralized grid to get it ready for the increased centralized nuclear generation after 2045. Distributed generation based on many small wind and gas installations, and their necessary expensive transmission connections and "smart" grid, is not sustainable. With a future grid powered by nuclear and hydro wind has no place. Wind needs gas. It makes little environmental, economic or technical sense to manoeuvre multi-billion dollar nuclear power plants and hydro facilities, with attendant wear and tear, to accommodate the vagaries of wind generation. All the $87 billion capital expenditure in the government's 20 year LTEP should be put into the centralized grid and nuclear where it will do the most good for the environment and for Ontario's economy.

In summary. Ontario should start planning now to get off fossil fuel use by 2045-50. A new LTEP is needed. The supplier of Ontario's new reactors should be made aware of the stringent requirements for load cycling and load following if Ontario is to wean itself off fossil fuels after 2045. Money should be put into improving the existing centralized grid rather than into the so called "smart" grid. Since it is unlikely that Bruce Power and Ontario Power Generation will include steam bypass improvements in their refurbishment plans if left to their own devices it will be necessary for the Minister of Energy, through the Ontario Power Authority, to mandate that they do so. This means delays in the refurbishment

schedule and extra costs that the nuclear-electric generators would be unwilling to accept. Contracts with these generators would have to resolve this issue, bearing in mind the benefits to be obtained by a significant reduction in fossil fuel use up to 2045-50 when the refurbished nuclear units are replaced by new nuclear build. All this has to be initiated now, now, now!

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