Today the EPA issued its first-ever regulation on carbon dioxide emissions from new power plants, limiting emissions to 1000 pounds of CO2 per megawatt-hour of electricity produced. Given the fact that the average coal plant vastly exceeds this limit (weighing in around 1,768 lbs CO2 per megawatt-hour), the implications of the move seem rather obvious – essentially banning new coal plants without carbon capture and sequestration (CCS) technology (and thus greatly increasing the cost of new coal plants), thereby making good on President (then-candidate) Obama’s promise to “bankrupt” anyone who still desired to build new power plants fueled by coal.
Naturally, the move is producing howls of protest from the predictable corners – despite the fact that the move only applies to new construction (with an exception for those already permitted and begin construction within one year of the rule change taking effect. And of course, despite the fact that there exists a reliable, baseload alternative for producing energy, one which incidentally has the lowest marginal generating costs and has proven more than capable of delivering electricity safely and reliably. More to the point, given that the chief opposition to the rule is from Republicans, who ostensibly support nuclear energy, why the doom and gloom about an economic catastrophe? If anything, the move should be an opportunity to hammering the case for why nuclear is needed now more than ever. Again though – one wonders if nuclear’s support is wide but shallow compared to support for conventional fossil sources among these groups.
Overall however, the EPA mandate has a marginal but positive impact on new nuclear, namely by formalizing the winnowing down of new baseload capacity to a race between nuclear and natural gas, the latter of which has of course been buoyed by low prices from the recent boom in shale gas production.
Meanwhile, if the EPA’s mandate is a glimmer of opportunity for the nuclear industry, it’s an outright giveaway for natural gas. The average natural gas plant emits roughly half the CO2 of a standard coal plant (about 850 pounds per MWh), and meanwhile the EPA estimates that 95% of current natural gas power capacity would pass muster under the new rules. Thus, the choice of a convenient round number of 1000 pounds per MWh seems all the less arbitrary – in fact it seems almost entirely designed to benefit natural gas at the expense of coal. (I was pleased to see that I am not the only one who noticed this distinction – the fine folks at NEI Nuclear Notes have also taken notice .)
There are perhaps any number of reasons to complain about the EPA rule, even if one does believe (as do I) that tackling carbon emissions is of the utmost importance. For one, a more economically efficient proposal would of course be a carbon tax. Logically, if the rule is designed to minimize the social ill caused by carbon emissions, then natural gas plants (as a function of capacity) all produce half the harm of coal plants, while nuclear produces none. More economically efficient policies – like a carbon tax – would more readily reflect this than the current approach, which almost seems designed to simply promote natural gas.
Indeed, MIT’s “Future of Nuclear Power” report found that even a modest carbon tax of $25/tCO2 would raise the price of new coal to 8.3 cents per kWh, comparable to that of new nuclear (8.4 cents/kWh), while that of natural gas would rise to 7.4 cents per kWh – still cheaper, although hardly the clear favorite, especially given scenarios under which the capital costs of nuclear were controlled to the level of other fossil sources (at which point, new nuclear drops to 6.6 cents per kWh – well below coal and slightly cheaper than natural gas.)
One can only guess then as to why EPA choose to ignore the advice of both numerous environmentalists and scores of economists, all of whom have advocated either a carbon tax (or its lesser cousin, a cap-and-trade carbon credit market) as an economically efficient solution in favor of a suspiciously non-arbitrary cap.
So will the rule prevent use of simple gas-fired combustion turbines? NREL says we’ll need many more of these under their 20% Wind scenario, due to their superior ramping rates (no boilers or steam pipes to warm up). According to EIA’s 2010 Electricity cost publication, the fuel consumption of these plants are:coal: 8,740 Btu/kWhrgas, combustion turbine: 10,450gas, combined cycle: 6,800 Problem?
That is a good question! I tried to look up numbers for this, and I think the answer is “no”, and I think this topic might deserve its own post sometime.Your heat rate for a coal plant sounds extremely good. I imagine this could be attainable for a new IGCC plant, and I’m guessing that’s what you meant. It should be noted that such a plant would pass the current EPA rule being discussed. I’m not sure the exact validity of these numbers, but I’m going to add the CO2 intensity by fuel.Bituminous coal: 0.0924 g CO2 / BtuNG: 0.053 g CO2 / BtuI don’t know for sure, but I think these numbers should be invariant of the plant type. There is the reality that much of the fuel is unburnt, but that’s the combustion physics/chemistry that I never formally studied myself.Multiply these numbers with the numbers you posted and you find that all of them come in under 1000 g CO2 / kWh. The only thing that is at real risk of not meeting the requirement are advanced coal plants like pulverized coal plants that are not quite as good as IGCC.NG CT still comes in at less than 600 g CO2 / kWh, and this makes pretty good intuitive sense. So build away according to the EPA.
Wait, I read the EPA number wrong. They gave 1000 lb/MWh, compared to the g/kWh I was using.That translates to 453 g/kWh. I like these units since it’s what the discussion about global warming on a international scale uses, although it doesn’t matter.But let me take back what I just wrote (and hopefully they’ll approve both these comments). No, you can’t build simple combustion turbine gas plants. Sorry.
Nathan,I favor increased use of clean natural gas to displace dirty coal.The NREL 20% wind scenario will reduce CO2/kWh by very little, because the increased, 24/7/365 operation in part-load-ramping mode (very inefficient) of OCGTs to ramp up when wind energy ebbs and ramp down when wind energy surges requires extra Btu/kWh and emits extra CO2/kWh that mostly offset what wind energy was meant to reduce.The total owning and O&M cost of wind energy must include costs of the wind turbines, their connection to and modification of nearby grids, or if remote, HVDC lines to population centers, extra OCGTs and CCGTs for backup and balancing, and increased management efforts by grid operators, etc.http://theenergycollective.com/willem-post/47519/base-power-alternatives-replace-base-loaded-coal-plantshttp://theenergycollective.com/willem-post/46977/impacts-variable-intermittent-power-gridshttp://theenergycollective.com/willem-post/57905/wind-power-and-co2-emissionshttp://theenergycollective.com/willem-post/59747/ge-flexefficiency-50-ccgt-facilities-and-wind-turbine-facilitieshttp://theenergycollective.com/willem-post/61309/lowell-mountain-wind-turbine-facility-vermonthttp://theenergycollective.com/willem-post/61774/wind-energy-expensivehttp://theenergycollective.com/willem-post/64492/wind-energy-reduces-co2-emissions-few-percent
Alan, Thanks for digging up the g/Btu numbers. They do seem like a problem for OCGTs; presumably someone (AWEA?) will or has asked them for an except for low capacity factor plants. The typical OCGT is only run at 5% capacity factor: they spin up for a few hours per day in the summer and are off the rest of the time (with big wind they’d run more). At above 20% capacity factor it’s cheaper to build combined cycle plants.
True that, as stated, the regulation seems incomplete. One would also think there would be a more elegant way to draft this legislation than to make such a cutoff. The cutoff isn’t arbitrary but it doesn’t take into account the other factors about the purpose of the units. As a case for grid reliability, a OCGT can’t really be argued with provided there is a need for it. I don’t think we have any other good options for 5% capacity units. I think most energy storage (like pumped hydro) still comes in at $1,000s / kW installed, which would demand a rather high capacity factor, or else we’ll be paying an extravagant amount for planning for the low probability moments of super high demand.
Willem,I think burning NG to make electricity is almost as ill-advised as burning oil. We should be building gas-to-liquids plants as fast as possible, and building as many CNG cars and LNG trucks as we can. When the fossil fuel era starts to taper off, transportation will be the last justifiable fossil fuel market.We pretty much know how to make all the energy we need with nuclear power and renewables. Unfortunately, for now we need to burn natural gas to make wind power practical, but that won’t always be the case. Eventually, we’ll have nuclear power plants with thermal energy storage and dispatchable hydrogen production.I have read many of your posts on wind, and as I recall, the poor compatibility with wind was mostly related to coal plants. The GE Flex-efficiency CCGT natural gas plant in particular claimed good performance with wind. But I do agree that wind costs more than is often claimed, once power transmission and other factors are included.
Nathan” The GE Flex-efficiency CCGT natural gas plant in particular claimed good performance with wind.”The unit is too slow ramping compared with OCGTs. As a result, its use as a wind balancer is limited. This is a sophisticated unit that should not be ramped up and down a hundred times per day, 24/7/365OCGTs operated below 50% are very inefficient. OCGTs need to operate at about 75% of rated output so a 200 MW unit can ramp from 150 MW to 200 MW or from 150 MW to 100 MW within about 5 minutes, for a ramp rate of about 25/5 = 5 MW/minute. Larger ramp rates are possible, but will more quickly wear out equipment.