By: Donald Jones, P.Eng., retired nuclear industry engineer.
There is to be no new nuclear build at Darlington so what impact does this have on Ontario’s greenhouse gas emissions from its electricity generating sector, on the future cost of electricity, and on the security of its future supply. From the discussion that follows undoubtedly emissions and cost will go up and the security of future supply will go down, by how much is for others to analyze. After all, Ontario’s Green Energy Act was designed to build up expensive wind and solar generation at whatever the price, rather than reduce greenhouse gas (GHG) emissions. In 2009 when the Green Energy Act came into effect Ontario was well on its way to becoming one of the world’s lowest emitters of GHGs because of the refurbishment of Bruce Power’s nuclear units 1 and 2 that was going on that would reduce gas and coal use. With GHG-free nuclear and hydro there was no need to waste vast amounts of money on wind/solar schemes that have little or no effect on GHG emissions.
Future generation will result in more operation of the frackgas-fired generators, all combined cycle gas turbine (CCGT) units except for one simple cycle gas turbine station and a few hundred Megawatts (MW) of inflexible combined heat and power generation. This will be more so during the 15 year long period of nuclear refurbishment starting in 2016 and with the additional loss of Pickering A and B in 2020 resulting in baseload operation of some CCGTs. Some frackgas-fired generation will be on line whether the wind is blowing or not and will be producing GHG emissions. Also expensive wind generation on the grid will be displacing cheaper GHG-free nuclear and hydro generation which makes little environmental, economic or technical sense. However, the Independent Electricity System Operator (IESO) will do whatever it takes to get the system it has been handed by the Ministry of Energy to work, even if it means manoeuvring nuclear stations to make room for wind. As stated in its latest 18-Month Outlook, issued 2013 December 12, “Flexibility, essential to the real-time balancing of supply and demand, is being addressed now through a variety of sources, including increased maneuverability of some nuclear units, demand response measures and new tools for managing wind and solar variability.” Instead of condemning wind the Professional Engineers Association in Ontario, like the IESO, accept wind on the grid as a given and support the manoeuvring of Ontario’s critical nuclear plants for its accommodation.The issue of wind and GHG emissions was raised before (reference 1). The question was asked, “Since the only people who know in detail how the generators on the grid are dispatched to accommodate wind are the people doing this job every day at the IESO they are the only ones who can come up with the answer to the question, ‘are wind turbine plants really reducing GHG emissions in Ontario and at what cost per tonne CO2 avoided?’ This really is the bottom line. It should not be too difficult for them to use computer simulation to compare typical daily load profiles with and without various amounts of wind generation and with various water storage levels and compare emissions as a result of their usual dispatching procedures and knowledge of the technical specifications/operating characteristics of the gas-fired generators.”
Apparently the IESO now has the tools to do the job even if it is not using them for GHG emission studies. This is evident from its latest 18-Month Outlook where the following was stated in the Executive Summary. “New energy modeling software has been used to produce an energy adequacy report, found in Section 4.3. The Energy Adequacy Assessment considers specific operating characteristics of all sources of supply, including variable resources. This provides the IESO with a better estimate of the sources of energy production that will likely be used to meet demand. The analysis also captures a broader spectrum of transmission constraints than is possible with a capacity analysis alone, as was the case in previous 18-Month Outlook reports.” Specific to gas, it says in section 4.3.1, “Gas units are modeled using heat rates estimated from historical offer data and its correlation with natural gas spot market prices.”
So maybe now the answer to the question can be confirmed which is, no, wind is not reducing emissions and if it is it is doing so at horrendous cost. If anyone (Ministry of Environment or Ministry of Energy/Ontario Power Authority) uses the IESO model to study GHG emissions they could model different postulated grid configurations, for example during nuclear refurbishment and with the Pickering A and B stations shutdown and during periods of reduced water level. Doing this would show the magnitude of GHG emissions from following the 2013 Long-Term Energy Plan without new build nuclear at Darlington. With a few assumptions the IESO model may also be able to tell how much the generation is costing Ontario.
If someone does undertake a study the method used in the model to calculate the GHG emissions may need to be revised, if not the emission numbers may be lower than they actually are. GHG emissions in kilograms (kg) are usually based on the total MWh of gas fired generation on the grid over a time period multiplied by an accepted kg CO2/MWh number based on the average heat rate of all the gas-fired units on the grid, which may be acceptable for units providing baseload with little power manoeuvring. However we need to take another look at the estimates of CCGT CO2 emissions for grids with large amounts of variable wind/solar power like Ontario. For example if there is 4,000 MW of gas fired-generation on a particular day it is extremely unlikely that this is coming from a few CCGTs operating at 100 percent power, likely the best efficiency design point. More likely it is coming from a lot of CCGTs operating at lower powers, higher heat rate (lower thermal efficiency), and consequently at a higher kg CO2/MWh, in order to get ramp capacity on the grid. CCGTs will seldom be operating at their most efficient design point in Ontario. Every time a CCGT is warming up gas is being burned while the gas turbine is slowly increasing power and warming up the heat recovery steam generators (HRSGs) and the steam turbine. This increases the heat rate giving higher kg CO2/MWh. If a CCGT had a bypass stack the gas turbine could be delivering power very quickly but at high heat rate since it would be operating simple cycle and giving higher kg CO2/MWh. Ontario’s CCGTs may or may not have bypass stacks. When increasing power (manoeuvring) in the operating range the HRSG and steam turbine metal have to be warmed up which takes away gas for no useful power output, increasing kg CO2/MWh. At higher ambient temperatures than the design temperature, in summer, the heat rate will increase resulting in higher Kg CO2/MWh, unless engineering is done to lower the air inlet temperature. Also the output will decrease since a gas turbine is a constant volume machine and power output depends on mass flow so more units would have to be on line to meet the demand resulting in more kg CO2/MWh. There will be more hotter days in the future with climate change. There are also power losses on the transmission lines from the CCGTs to the load centres where the MWs are needed resulting in higher kg CO2/MWh. People don’t want CCGTs in their backyard! As CCGTS age heat rate increases so kg CO2/MWh increases. It is not known whether the present CCGTs were designed for manoeuvring or not. If they were designed for baseload then manoeuvring to cater to variable wind could increase wear and tear and increase kg CO2/MWh and reduce their operating life. On top of this we have the frackgas (methane) production/transmission losses and maybe emissions from flaring resulting in GHG life cycle emissions that may be comparable to coal. The low hanging fruit of conservation has already been picked as a result of high electricity prices, the major or only incentive for any conservation program, so no more significant savings in peak demand period frackgas use to reduce GHGs will come from this area. More money being spent on conservation will result in less and less benefit. Industrial and residential Demand Response programs have limitations when it comes to GHGs. If the energy not used is simply transferred to later in the day some gas-fired units would still be operating, producing GHGs.
Ontario cannot rely on GHG-free hydro electricity imports from Quebec. The carrying capacity of the lines to the southern Ontario load centres is limited. Even if all equipment is operating this cannot exceed about 2,750 MW and more likely closer to 2,000 MW in actual practice. GHG-free hydro from Manitoba is even more limited, about ten percent of that from Quebec, and a long way from southern Ontario load centres. Since the Quebec grid is not synchronous with the Ontario grid the connection is more complex than Ontario’s connections to New York and Michigan for example because the isolation of the Quebec grid requires complex converter substations. Quebec depends on a very few long distance transmission lines to bring power from its dams to its load centres. This makes the supply less reliable than a supply from generators closer to the load centres, like nuclear. Climate change could reduce hydro output from Quebec’s, and Ontario’s, dams. Imports from Quebec would depend on Quebec’s own demand for power, summer (air conditioning) and winter (heating), and on its exports to the U.S. who would always offer a better price than Ontario. Even though frackgas powered generation in the U.S. is cheap right now, and impacting on electricity exports from Quebec, this scenario is unlikely to last.
Gas prices will increase. The conventional gas supply from Alberta to Ontario is running down and is being replaced by frackgas. Well depletion rates for frackgas are high resulting in the need for more and more wells. It is said that production costs at the moment with some companies are more than the market price, being subsidized by sales of other commodities like oil. This cannot continue. The building of liquefied natural gas plants to export gas to areas of the world where the price is several times the domestic price will put up the price significantly in the future. Because of its present low price the demand for gas will increase in the road and rail transport sector, where it has clean burning advantages, and in the petrochemical industries. Pollution regulations in the U.S. have resulted in new frackgas-fired generating stations being built to replace coal. Changes in the economics of world trade due to increases in price of goods from foreign countries due to wage increases, increased energy costs, and transportation costs would result is more manufacturing being done in North America with increased demand for gas. As demand increases so will price, putting up home and industry heating costs as well as electricity costs. The price of frackgas generation in Ontario’s dysfunctional electricity market is high anyway, much more than nuclear and hydro, due to capacity payments to the larger CCGT operators who get paid whether they produce electricity or not. Higher frackgas prices just add to the bill. Export customers pay only the market price of generation which is about a quarter of the price paid by Ontarians. This is because Ontario consumers pay a Global Adjustment fee to account for the difference between the low market price and the high cost of servicing the various contracts with the electricity suppliers.
Storage for wind energy to reduce CCGT usage will not help. It is not economic or practical and may be environmentally unacceptable. It would just increase the cost of an already expensive and unneeded energy source. If economic storage were practical it would have been developed long ago to use the cheap surplus generation at night and weekends from inflexible but efficient baseload generators so that some more efficient baseload generation could be added to the grid. Storage schemes include the usual suspects, hydrogen, thermal, compressed air, pumped storage, batteries, flywheels and whatever. With no storage silver bullet Bruce Power invested in improving the robustness of the turbine steam bypass system of its nuclear units to avoid shutting down units at night when demand is low and when wind generation could be high. This reduced the number of times a unit would have had to be shutdown and then be unavailable for two to three days during which time polluting gas-fired generation would have had to be used. This investment enabled significant output power reductions to be made and is helping the IESO manage its frequent periods of surplus baseload generation brought on by wind generation, low demand, and increased amounts of hydro during the shoulder seasons. In the future such nuclear flexibility will enable more flexible nuclear to be accommodated on the grid (reference 2). The IESO said in a 2013 Dec. 12 News Release, “The IESO will continue to look for new opportunities to add flexibility into the market to support reliable and efficient operation of the electricity grid“. If it means this it should take steps to enable the Darlington nuclear units to become as flexible (or more flexible) as the Bruce nuclear units even though manoeuvring nuclear to accommodate variable wind makes no real sense. Obviously the lost generation from steam bypass on the Bruce units, deemed generation, has to be paid for. If some silver bullet storage mechanism could be developed it would make more sense to apply it to the province’s nuclear plants and scrap the unreliable wind generation that is not needed anyway. Given the expense of the large amounts of MWh storage required it is more economic just to pay for deemed generation from the present flexible nuclear units.
With the increasing demand for non-renewable frackgas the effect of short and long term supply shortages and price increases on the space heating needs of homeowners and industry must be examined. Using frackgas for heating and for electricity generation in North America should be an obvious life and death concern given Ontario’s cold winters. A “short” term plan would be to stop using frackgas for electricity generation to ensure supplies for home heating. However Ontario is part of North America and has no control over how other jurisdictions use and waste gas. Space heating furnaces need gas and electricity to function. Buildings cannot be heated efficiently by gas alone but they can be heated by electricity alone and we are certainly not going to run out of electricity. A long term plan for Ontario would move home heating off gas to electricity (like Quebec) with energy efficient homes and expanded use of ground source heat pumps (like Manitoba) at least for multi-residential units, commercial operations, hospitals etc. The next Long-Term Energy Plan must look at this in detail. The 2013 Long-Term Energy Plan expects conservation and efficiency improvements will almost take care of energy demand increases (MWh) up to 2032 but this ignores the effect of climate change which will give more very hot days that will require more power (MW) to meet these extended peak demands. Neighbouring jurisdictions will also be affected by such extreme weather. Conservation will not be on the mind of consumers during these extreme weather events that will be happening more frequently. Only by building more nuclear, much more, will Ontario be isolated from the effects of the prolific use and waste of non-renewable gas in North America. Note that Russia is maximizing its hydro and nuclear generation in order to free up more (nonrenewable) natural gas for export to Europe. Maybe when the gas runs out or becomes too expensive they can export nuclear electricity to Europe instead!
Subsidized electricity exports, inefficient and costly operating modes of the wind balancing CCGTs (that partially or completely negate any savings in greenhouse gas emissions from wind, even more so with increasing frackgas use), capacity payments to gas-fired generators just to ensure they are there when the wind drops, spilling clean low cost baseload hydro, powering down clean low cost nuclear, paying for expensive wind generation when it is not needed, new transmission infrastructure to connect up wind, and the parts of the so called smart grid needed to incorporate the wind, are all part of the increasing costs due to unreliable wind. The real cost of wind to Ontarians is very much more than the 13.5/11.5 c/kWh paid to the wind generators and with 10,000 nameplate MW of wind/solar being installed by 2021 costs can only go up. The cost of all the Conservation/Demand Response programs and the cost of various studies initiated by the IESO and the Ontario Power Authority to support/promote integration of wind/solar into the grid should also be thrown into this mix called the Global Adjustment, the major part of the generating cost. And don’t forget the advertising costs for these conservation programs.
Having 10,000 nameplate MW of wind/solar (about 8,000 MW of wind, say) coming onto the grid will pose operating concerns for the IESO since sufficient MW of quickly available standby power would have to be available if the wind dropped – the IESO relies on its centralized wind forecasting system to give them a heads up on this, let us hope it is accurate. The availability of this quickly available standby generation could limit the amount of wind generation allowed on the grid during high demand and high wind generation days that would result in payment to the wind suppliers for the generation that could not be used, deemed generation. Maybe the IESO’s new energy model, referred to earlier and that likely wouldn’t be needed but for wind (add to Global Adjustment pot!), could be used to determine the optimum amount of wind generation for the grid so that no wind would need to be curtailed on windy high demand days. This might be less than the 8,000 nameplate MW of wind planned.
So, with no new nuclear and no reliable imports of clean hydro Ontario is stuck with more gas and wind that will inevitably lead to increased GHG emissions and costlier electricity. New nuclear build would provide Ontario with a secure independent supply of GHG-free electricity at stable competitive prices for the foreseeable future. This will incent investments in the manufacturing sector and development of the resource sector and keep us warm in winter and cool in summer.
1. IESO – will Ontario’s wind turbine power plants reduce greenhouse gas emissions?, Don Jones, 2010 August 23 http://ontario-wind-resistance.org/2010/08/23/ieso-will-ontarios-wind-turbine-power-plants-reduce-greenhouse-gas-emissions/
2. An alternative Long-term Energy Plan for Ontario – Greenhouse gas-free electricity by 2045, Don Jones, 2011 May 30,http://coldaircurrents.blogspot.ca/2011/05/alternative-long-term-energy-plan-for.html