Marrying Gas and Renewables A Turkish developer recently announced that it would build a new power plant using technology from GE that matches wind and solar generation to the output of a highly responsive natural gas turbine, all integrated in one package with the hardware and software to mesh its output with the grid. GE is apparently calling this scheme IRCC, for “integrated renewables combined cycle“, adding yet another acronym to our growing list of energy choices. This development looks interesting from a technical perspective, but also for what it suggests about GE’s view of the future market for generating equipment and power delivery.
The International Energy Agency’s “Golden Age of Natural Gas” scenario remains a question mark, rather than a certainty, but if gas is to serve as the key fuel for bridging between our high-emission present and the low-emission future, then we’re likely to see more installations like the one in Turkey emphasizing the synergies between gas and renewables, rather than the tough competition gas is giving renewables in some markets. The IRCC–not to be confused with an IGCC or the IPCC–is interesting because it goes well beyond the idea of using gas-fired power plants to back up the naturally variable output of wind farms and utility-scale solar arrays.
The IRCC concept is built around a new combined cycle gas turbine, the Flex-Efficiency 50, with an impressive capability to ramp up and down, as needed, with minimal loss of either efficiency or emissions performance. And thanks to the energy technology portfolio the company has built up over the last decade, GE is able to offer one-stop shopping with GE wind turbines and a solar thermal generating module from eSolar, in which GE has recently invested. The gas turbine/solar thermal hybridization looks especially useful in maximizing plant efficiency and incorporating solar thermal power into the grid at the lowest possible cost, by avoiding the expense of an extra steam turbine and generator. If all this works as advertised, the grid operator shouldn’t know or care whether the power being dispatched was generated using wind, sun, or gas.
Before you confuse this posting for a GE ad, I should note that at least in the configuration chosen for the Turkish site most of the power from this integrated plant would still be generated by the gas turbine, which has 10 times the peak output of the concentrated solar power module and more than 20 times the rated power of the small wind farm tied into it. By the time you account for the capability of the gas turbine to run 24/7 when necessary, compared to typical capacity factors of 25-40% for wind and up to 25% for solar, the proportion of the IRCC’s annual megawatt-hours generated from gas could exceed 95%. Nor is GE the only firm bringing turbines like this to market. So it’s an impressive step, though more of an incremental than revolutionary one. However, with its inherent flexibility, I wouldn’t be surprised if this type of gas turbine could effectively integrate a much larger quantity of renewable generation on the grid outside the IRCC’s fence, particularly after the operating experience of the first few installations has been absorbed.
GE’s timing in introducing its IRCC concept could prove especially apt. Not only does the Flex-Efficiency turbine look useful for helping to meet California’s aggressive new 33% renewable electricity target, but the 50-cycle version featured in GE’s marketing materials–likely minus the solar thermal module–could be just what Germany needs, now that its government has begun to come to grips with the quantity of new fossil generation that’s going to be required to make up for the post-Fukushima accelerated retirement of its nuclear power plants.
The new plant, set to start producing energy by 2015, will combine the best of both worlds: solar and wind on one hand, and natural gas on the other. The company says this combination would make sense financially and doesn’t expect subsidies to nor to encourage its building or future energy production.
“When we look at the long-term future of power generation, we see the importance of integrating natural gas and renewable energy sources in new and innovative ways to provide energy that is cleaner, more cost effective and more reliable,” explained Paul Browning, in charge of thermal products at GE.
With development to start later this year, GE is hoping its 70 percent efficient natural gas part of the power plant will seamlessly complement wind and solar, in an aim that will probably set away some of Turkey’s focus from nuclear power.
Last week was a good one if you happen to own a natural gas well. Two reports on the outlook for natural gas, both in the U.S. and worldwide, gave a glowing assessment of the fuel’s future prospects. The International Energy Agency (IEA) cheekily titled its report, “Are We Entering a Golden Age of Gas?” The conclusion: global gas use will rise, in one scenario, by more than 50 percent by 2035. So, yes, it would seem the “golden age” is nigh. Meanwhile, the U.S.-centric report from the M.I.T. Energy Initiative, “The Future of Natural Gas” blasted critics who claimed that gas, when it comes from shale formations, is worse for the environment than coal.
Of course, your impression of these reports may differ if you’re a climate change activist rather than, say, a Chesapeake Energy shareholder.
The IEA report, for example, concluded that increasing use of gas puts greenhouse gas emissions on a trajectory to stabilize at 650 parts per million, which would bring a long-term temperature rise of 3.5 degrees Celsius. This figure, by any measure, is an unacceptably high level of warming and made Climate Progress blogger Joe Romm, very unhappy: “Absent a high CO2 price,” Romm wrote, “gas displaces as much low-carbon electricity as it does high-carbon coal.” But there are many reasons to think Romm and IEA are being overly pessimistic. While it’s clear that an elevated carbon price – for example, a carbon tax – would incentivize the adoption of renewable energy, gas could, in the near term, mean the end of coal as a major fuel source. It can encourage the adoption of renewables along a realistic timeline – one that allows green technology to catch up with green ambition. Here are some reasons why:
1. Natural gas enables renewable energy. Natural gas power plants can fire up quickly and adjust their power output rapidly. That makes them the ideal dance partner for wind and solar, which are variable energy sources. There may be a time in the next few decades when renewable resources don’t need fossil fuel backup, but we’re not there yet.
2. Renewable portfolio standards (RPS) mandate renewables. A growing number of states and countries are requiring a certain percentage of wind, solar and other non-fossil fuel on the electrical grid. In California, for example, that target is 33 percent renewable energy by 2020. In the European Union, the target is 33 percent by 2020. As long as legislators hold the line on those mandates, natural gas can’t crowd out renewables.
3. Integrated Solar Combined Cycle is crazy efficient. Modern natural gas plants working in combined cycle – a configuration that uses waste heat to drive a steam turbine – have efficiency ratings in the upper 50 percent/60 percent range. Introduce concentrated solar power (CSP) to the equation and efficiency can shoot up to 70 percent. How? CSP uses mirrors, or heliostats, to direct sunlight that boils liquid in a central tower. The steam then drives a turbine to create electricity. In this new configuration, the CSP can share the steam turbine and increase the efficiency of the system without burning any more fuel. General Electric, this magazine’s sponsor, has teamed up with CSP pioneer eSolar to introduce this technology.
4. Carbon Capture and Storage (CCS) is advancing. CCS is often discussed in conjunction with coal but the technology, which involves storing carbon dioxide from power plants underground, has perhaps even more potential for natural gas
This technology actually works – it’s been tested and proven at multiple sites – but is still too expensive to deploy at scale. While some in the environmental community think utility-scale CCS is a Macguffin, others believe it has enormous potential for decarbonizing energy if costs can be brought down.
5. Methane emissions from natural gas can be curbed. Recent attacks on natural gas have focused on leaks of methane, the principal component of gas and a potent greenhouse gas, during its lifecycle – the drilling, transportation and end use. While the most dire scenario of lifecycle emissions has been discredited by some researchers, methane emissions remain a problem. But it’s possible to recapture the leaking methane and there is an incentive for industry to do it, since this is fuel that can be sold.
6. Gas plants can, and likely will, knock out old coal plants. This is a point made in the IEA report but it’s worth stressing. In the U.S., tightening emissions regulations will make coal plants expensive to retrofit and natural gas plants, which emit about half the carbon dioxide, will likely pick up the slack. The emissions savings in the United States could be 150 million tons of carbon per year if 66 gigawatts of coal plants are replaced, according to one estimate. Just Thursday, one utility, American Electric Power of Ohio, announced plans to shut down five coal-fired plants by 2014 to comply with the new guidelines.
7. There is a lot of idle natural gas capacity on the grid. Those power plants are of a relatively recent vintage – most were built in the 1990s – so they’re efficient. This means that the emissions savings from natural gas are already built into the system, they just need to be activated. M.I.T. researchers believe total carbon emissions in the U.S. could decrease by 8 percent if natural gas plants are utilized at a higher level.
8. China has a lot of natural gas, which is a good thing. For all the talk about China’s renewable power ambitions, right now coal is the superpower’s fuel of the future: gas is expected to represent 63 percent of primary energy consumption by 2015. Continued dependence on coal will have disastrous consequences both for carbon emissions and for pollution in China’s already smoggy megacities. Tapping China’s vast gas resources could help make cities cleaner and electricity generation less carbon intensive.
LONDON (Reuters) – A move to natural gas and renewable energy will be a global long-term trend, even though technology such as wind power is currently more costly than fossil fuels and nuclear, a General Electric executive said. GE is well placed to estimate relative costs as one of the world’s biggest suppliers of all major power technologies.
“GE believes we are seeing a megatrend in natural gas and renewables. These two trends will be long-standing ones, which we will be investing in,” Paul Browning, vice president of thermal products for GE’s power and water division, told Reuters in an interview on Friday.
“In the future, we will need a bit of everything, but gas is certainly going to be an advantaged fuel because unconventional (shale) gas is changing the dynamics.”
The International Energy Agency said this week that rising gas supplies from unconventional sources could encourage demand to rise to levels exceeding coal by 2030. However, coal is the cheapest form of power generation of all, a fact borne out by energy statistics from oil major BP, which show that world coal consumption last year reached a new record, with 50 percent more burned than in 2000.
The U.N. climate science panel, the IPCC, said in 2007 that global greenhouse gases must peak by 2015 to hit safer climate change targets.
But soaring coal demand instead pushed up Chinese CO2 emissions by more than 10 percent last year, according to BP.
DRIVING DOWN COSTS
While the cost of wind power is falling, making it a long-term prospect for investing, it still lags gas, coal and nuclear power, Browning said.
The cost of generating electricity includes the up-front capital cost of building a power plant plus ongoing fuel costs. Those costs can be combined in a term called the levelized cost.
The levelized cost of onshore wind was around 9-10 U.S. cents per kilowatt hour (KWh), said Browning, or about double the cost of the cheapest form of coal-fired power generation at 5 cents, and also above 6 cents for U.S. natural gas and 7-8 cents for nuclear.
He saw the levelized cost of solar PV at about 15 cents.
GE wants to drive down the costs of technologies such as solar thermal and integrated gasification combined cycle (IGCC) coal technology, but natural gas will be in abundant supply for at least the next 25 years, making it the cheapest energy source.
This week, Turkish private equity firm MetCap Energy Investments said it would use GE technology to build a $500 million power plant in Turkey that will use both gas and renewable energy.
The plant will integrate a gas turbine, a steam turbine, 22 MW of GE wind turbines and 50 MW of solar thermal technology.
“Stand-alone concentrated solar thermal is fairly expensive right now — in the 15-20 cents per KWh range,” Browning said.
“But when you integrate solar thermal with a combined cycle power plant, the infrastructure is already there. That makes integrated solar combined cycle costs competitive with photovoltaic (PV) solar, and they start to get closer to (onshore) wind,” he added.
GE is also aiming to drive down the cost of IGCC technology, which burns coal after turning it into gas, improving power conversion efficiency and thereby reducing carbon dioxide emissions.
IGCC levelized costs are currently around 15 cents/KWh, but GE hopes to lower the cost to 8-9 cents, partly through a joint venture with China’s Shenhua Group Corporation to develop the technology.
For natural gas, the stars are aligned for it to play a far more substantial role in the world energy mix, according to a pair of reports this week.
The Massachusetts Institute of Technology today published its report on natural gas, which it characterized as an abundant and reasonably priced resource able to act as a bridge to a low-carbon future. The International Energy Agency released its own study (PDF) Monday, where it said natural gas is poised to enter a “golden age.”
The key driver for the optimism around natural gas is supply as well as societal pressure to cut greenhouse gases and transition away from dirtier fossil fuels. Although there are considerable uncertainties, MIT estimates there are about 150 years’ worth of natural gas available at current consumption rates. Burning natural gas produces about half the carbon dioxide as burning coal and has much lower levels of mercury and air pollutants.
Natural gas has become a favored energy source for many politicians in the U.S. because it’s cleaner than coal and is domestic. Even without laws that put a price on carbon emissions and an unknown supply, the abundance and versatility of natural gas–which can be used for electricity, heating, or transportation–means that its use will grow significantly, according to both the MIT and IEA reports.
In the U.S., the energy picture has been dramatically changed over the past few years by tapping so-called unconventional resources of natural gas locked in shale rock. Russia, the Middle East, and the U.S. contain altogether an estimated 70 percent of supply, according to MIT.
“Gas is, globally speaking, a very young industry with a very bright future ahead of it,” said Anthony Meggs, the study’s co-chair and visiting engineer at the MIT Energy Initiative, during a presentation today. “Shale gas is transformative for the economy of the U.S. and potentially on a global scale.”
He said that it’s difficult to pinpoint the actual amount of known reserves, particularly unconventional sources outside the U.S. Drilling from shale has shown to be highly variable with some wells being less productive than expected before drilling, making them uneconomic. One of the recommendations from the report is further government-funded research into understanding natural gas reserves.
Impact on renewables, nuclear
Although natural gas is considerably cleaner than coal, drilling shale gas in the U.S. has been marked with growing environmental concerns over the past few years due to the practice of “fracking,” where shale rock is cracked and then released by pumping fluid into wells.
The primary concerns with fracking are preventing gas from entering water aquifers with faulty well casings and treating fracking wastewater, Meggs said. MIT said that environmental concerns are “challenging but manageable.” Meggs said that drilling companies should disclose the fluids and that regulations should better address environmental issues.
“It’s a big threat. The industry is doing a very poor job of organizing a coherent response to a very concerted campaign, or series of campaigns,” he said. “Common sense means that less environmentally sensitive oil and gas companies (of which there thousands drilling shale gas) will lose their license to operate there…and they will gradually be squeezed out.”
In recent months, there have been questions, notably from a study on lifecycle emissions from Cornell University, as to whether leakage of the potent greenhouse gas methane–the main component in natural gas–during drilling means that natural gas is a bigger contributor to global warming than coal.
The study’s authors today said that even with recent revisions on emission estimates from the EPA on leakage, natural gas is still substantially cleaner. The study projects significant greenhouse gas benefits by replacing older, inefficient coal power plants with more efficient gas plants.
Although natural gas is often characterized as a bridge to a low-carbon energy supply, the low prices of natural gas pose a barrier to renewable energy and nuclear for electricity generation. “The gas price is sufficiently low that it makes it very tough for nuclear or renewables to take market share,” said Henry Jacoby, MIT management professor and co-chair of the study.
Even without climate policies or mandates for cleaner energy, natural gas usage will go up in the U.S., he said. Coal accounts for about 50 percent of electricity generation, compared to 23 percent from natural gas.
Substituting natural gas for coal in commercial and industrial boilers can deliver relatively quick return on investments of a few years, said Melanie Kenderdine, executive director of the MIT Energy Initiative. Buildings account for 55 percent of natural gas demand.
MIT researchers are not bullish on natural gas for vehicles, as is called for in the revised Pickens Plans for fueling long-haul trucks with natural gas. They say there isn’t a fueling infrastructure, and that there is a substantial incremental cost to converting trucks, as well as a long payback period.
A power plant planned for Turkey will use a combination of energy sources–wind, solar, and natural gas–to deliver round-the-clock electricity service.
General Electric today said that it will supply the equipment for a 508-megawatt plant to developer MetCap Energy, which expects to complete the project by 2015. The plant in Karaman, Turkey, is projected to power more than 600,000 homes.
The project is unusual in that a single facility will draw on three sources to deliver “baseload” power, or the power needed to meet the continuous energy demand for the area. GE said that the plant’s overall efficiency will be 66 percent, higher than a modern natural gas plant.
GE is touting the project as a showcase for its FlexEfficiency power plant system anchored around a natural gas turbine designed specifically to ramp power production up and down to accommodate variable wind and solar power.
The other main power-generating components are GE wind turbines capable of producing 22 megawatts and a 50-megawatt eSolar concentrating solar thermal plant. GE yesterday announced that it invested in California-based eSolar and has a license to use eSolar’s solar technology for hybrid power plants. eSolar plants generate heat with thousands of sun-tracking mirrors to produce steam, which is driven through a turbine to make electricity.
MetCap Energy Investments chose the GE system because it’s a relatively clean source of energy and is efficient with water as well. “In addition to record-setting fuel efficiency, this power plant will have zero liquid discharge, low emissions, and a rapid-response, 28-minute start capability,” said MetCap Energy Chairman Celal Metin in a statement, adding the project will yield “attractive returns on our investment.”
GE said it expects to see more interest for power plants that combine renewable energy with natural gas. Some power plant project developer are using energy storage, such as large batteries, to ensure a steady flow of power although batteries for bulk storage are expensive.