Tuesday, 27 March 2012

New Source Performance Standards: The Start of U.S. Climate Change Regulation?

Back in 2007, the United States Supreme Court ruled that greenhouse gases like carbon dioxide are air pollutants covered by the Clean Air Act.  That ruling gave the U.S. Environmental Protection Agency (EPA) the authority to issue an "endangerment finding" if the agency determined that greenhouse gases are a threat to public health and the environment.

This was a particularly tricky issue, because the health and environmental impacts from increased greenhouse gas concentrations are indirect, as opposed to pollutants like ozone, which directly harm living organisms or sulfur dioxide, which acidifies lakes and streams.  Nevertheless, in 2009 the EPA issued just such an "endangerment finding", opening the door for direct regulation should Congress fail to pass legislation reducing greenhouse gas emissions.

Now, five years after the original Supreme Court ruling, the EPA is finally preparing to exercise its authority to regulate emissions from power plants.  The agency is expected today to issue New Source Performance Standards that limit carbon dioxide emissions from newly constructed power stations to 1,000 pounds per megawatt-hour of generation.  For those more accustomed to metric units, that's about 0.45 tonnes CO2/MWh. A combined cycle natural gas power station can have emissions below 0.40 tonnes CO2/MWh and so is not likely to be affected by this regulation.

Other fossil fuels will face greater challenges.  If the rule stands, it means no new traditional coal-fired power plants will be built in the United States.  A typical coal-fired power station releases can release 0.90 tonnes CO2/MWh, or more.  To operate within the New Source Performance Standards, such a plant would have to generate half its power with renewable biomass fuels (physically possible for no more than a handful of power stations).  Otherwise they would need to employ carbon capture and storage (CCS) - a technology that may yet take decades to beome commercially viable - to bury the CO2 deep underground.

The EPA's New Source Performance Standards would grandfather existing power stations, and allow them to keep operating and undergo  retrofitted even if they exceed the emissions thresholds.  However, they still serve a useful purpose by setting a timeline for the gradual phaseout of these plants.  A power station can operate for 50 years or more, so the investment decisions we make now lock us into a decades-long emissions path.

When it comes to climate change, we're already at the bottom of a deep hole.  The EPA's new ruling is a signal to power plant operators that we need to stop digging.

Thursday, 22 March 2012

Heat Wave 'Rewrites History' Across the U.S.

We're two days into spring, and already it feels like summer across much of the United States.

In Chicago yesterday, the temperature reached 87F (about 30C), the hottest it has ever been this early in the season.  The temperature has exceeded 80 degrees seven times in the last eight days. The average high temperature for this time of year is 49F (9C).

Milwaukee  has experienced its warmest March day ever.  In Caribou, Maine, the average high temperature is 36F (2C); yesterday it was 75 degrees (24C).

So yes, it's hot.

Is climate change to blame?  It's impossible to point to any one weather event and say whether or not we can attribute it to climate change.  But these types of temperature extremes match the predictions of climatologists, who expect the Midwestern US to get hotter and drier over the next few decades.

The heatwave isn't definitive proof of climate change, but it provides us with a 'teachable moment'.  This is weird weather, and everyone is talking about it.  The heatwave comes on the heels of an unusually mild winter, last summer's drought across the Southeast and fires in Texas, floods on the Mississippi, and more.  Each one of these was a "once in a century" event, but they keep coming.

People are beginning to realize that these freak events are becoming more common.  And they have a real impact in lives and money.  Perhaps more of us are beginning to wonder whether we're better served investing in measures that fight change rather than spending to clean up after the fact.

Friday, 16 March 2012

Renewables and Nuclear: Different Signals from Germany and Britain

On 11 March, one year on from the Fukushima Daiichi nuclear reactor meltdown in Japan, Germany has reaffirmed its decision to abandon nuclear power.  The Germans shut down their eight oldest reactors shortly after the Japanese earthquake, tsunami and reactor core breach, and pledged to shut the remaining reactors by 2022.

In the short term, this has meant an increase in greenhouse gas emissions from fossil fuel power stations in Germany and neighboring countries.  Over the longer term, however, Germany's leaders want to replace the country's nuclear output with renewables.  Critics doubt the nation's electric grid can transport power from new renewable energy generators to power-hungry factories hundreds of miles away, but the initiative has the support of 76% of the public and Chancellor Angela Merkel has pledged to redouble her government's efforts.

The very next day, the Guardian newspaper reported that the British government wants to reduce the relative priority given to renewables over nuclear.  The Guardian reports that the UK has proposed to the European commission that explicit renewable energy targets for 2030 be dropped in favour of targets for "low carbon power".  This label would allow countries to choose whether they wish to reach climate change - related power targets with renewables, nuclear power, carbon capture and storage or a combination of the three.  While this change doesn't necessarily mean the British government would back away from its support of renewables, it leaves the door open for such a move.  In fact, this policy pressure would not make sense otherwise.

Just the possibility could have a chilling effect on investment in renewables in the UK.  Most renewable energy technologies are characterised by high capital costs and low operational costs.  The cost of renewables-based electricity can be cost-competitive or even superior to f that from ossil fuels, but only when those up-front costs and long-term savings are averaged over many years.  Without certainty that government will maintain its support for years or decades, investors are less likely to provide the millions, or even billions of pounds required to bring renewables to market on a large scale.

Nuclear power generates significantly lower carbon emissions than fossil fuel fired power stations and - despite Fukushima - it is a proven technology with a global track record.  However, it is by no means certain that the government will be able to overcome long-term opposition to nuclear power and nuclear waste in time to ensure that nuclear can play a significant role in Britain's lower-carbon future.

It would be unfortunate if government policy shifts damaged commercial support for renewables without providing sufficiently for a viable alternative.

Tuesday, 6 March 2012

Beyond Compliance: Green Monday and the Rise of Corporate Action

For the past year, Carbon Clear has been a sponsor of Green Monday, a UK-based corporate sustainability networking event. Once a month, 300-500 sustainability professionals and corporate executives get together to share their experiences implementing programmes aimed at making the world a better place.

The topics tackled by this group are ambitious.  Last night we heard from a U.S. company that provides an online platform for peer-to-peer car sharing. Think Zipcar or City Car Club, but scalable to reach every town or village in America.  Members buy fewer cars (reducing overall resource and energy use) because they don't need to have a vehicle sitting in their driveway when they want to get from Point A to Point B. A second sustainability benefit comes because the costs of car ownership become variable rather than fixed costs.  Car owners pay the cost of their vehicle and insurance whether they use it one day a year or every day - which makes the incremental cost to drive an additional mile quite low.  Car share members, by contrast, pay only for what they use, with the result that members drive relatively less and cycle, walk or use public transportation more.

Another Green Monday delegate works for a major pharmaceutical company that is, rather counter-intuitively, investing in sewerage and water supply infrastructure in developing countries. The company's CEO made a committment to provide medicines to treat water-borne diseases at cost, which is a common practice among pharmaceutical firms. Interestingly, the company has since found that it made even better sense to spend their money shoring up local infrastructure to prevent those diseases from occurring in the first place.

A third company is working to get people out of cars and airplanes entirely, by tackling the technical and financial challenges to high quality videoconferencing.  These initiatives and others like them have the potential to save millions of tonnes of carbon emissions and improve the lives of tens of millions of people around the world.

What is striking about the Green Monday discussions is the relatively low profile played by senior government policy makers, and how rarely delegates representing hundreds of major corporations cite government regulation as a spur to action on sustainability.

Governments do have a critical role to play in support of environmental sustainability.  They provide a democratic mechanism for setting local and national priorities, and can ensure that measures that help the environment don't have a disproportionate impact on poorer people.  What is more, governments can correct market failures by putting a price on environmental damage through fines and penalties, cap-and-trade mechanisms, and taxes.  When it comes to climate change and a number of other global challenges, however, market failure has been compounded by policy failure.  Governments around the world have been deadlocked for the past decade over a global agreement to limit greenhouse gas emissions that will replace the Kyoto Protocol when it expires in December 2012.  Despite an urgent need to change course, carbon emissions continue to rise, and a host of natural resources, from water to petroleum and topsoil grow increasingly scarce.

Green Monday and similar initiatives show that we don't have to wait for government regulation before we take action.  Companies can go beyond compliance to deliver solutions that enhance the environment, inspire their staff and customers, and directly or indirectly improve their bottom line. It's encouraging to see more and more business set ambitious sustainability targets and devote corporate resources to achieving them.

Friday, 2 March 2012

Making Renewables Work: Energy Density

Most discussions about renewable energy are rather abstract.  Analysts talk about increasing the share of renewables-based electricity generation from 3% to 15% of the national total, or installing a million solar roofs.  The renewable energy industry, meanwhile, talks about product specs: 250-Watt solar panels and 750 kW wind turbines.

But what does that mean for the average household or business user?  How can we make the potential of renewable energy accessible to the average person?

Energy density provides one useful way to think about the contribution that renewables can make.  Put simply, every power generation technology requires a certain amount of land (or ocean) area, whether it is a wind farm, solar PV panel, hydropower plant or coal-fired power station.  Dividing annual energy production by that land area gives us a rough measure of energy density, measured in kWh per square meter per year.

According to an analysis performed by the U.S. National Renewable Energy Laboratory (NREL) on 172 large windpower projects, average power density on these windfarms averaged 3 megawatts per square kilometer, including the area around the turbines, access roads, and the like.  Because wind is intermittent, annual energy output averages only around 30% of the theoretical maximum.  This means these 172 wind farms had an average energy density of approximately 8 kWh/m2 per year.

In the UK, each square meter of ground receives around 1,000 kWh of solar energy per year.  Solar PV panels convert this to electricity with an efficiency of around 10%, giving an energy density of 100 kWh/m2 per year.

The old Sizewell A nuclear reactor in the UK, by contrast, comprises a 99 hectare (990,000 square meter) estate, and had a rated power output of 427 MW.  With a 90% annual availability and a electricity conversion efficiency of 35%, this boils down to an energy density of a bit more than 1,000 kWh/m2 per year.

To summarize:
  • Large wind: approx. 8 kWh/m2 per year
  • Solar PV: approx 100 kWh/m2 per year
  • Nuclear: approx 1,000 kWh/m2 per year
One of the things energy density tells us, then, is that we need more than ten times the land area to generate the same amount of energy each year from wind than from solar power, and we need ten times the land area to generate the same amount of electricity from solar than from nuclear power.  Nuclear power is significantly more energy dense than renewables.

That isn't the whole story, of course.  The land area used for wind farms isn't completely consumed by the turbines.  Wind turbines may be sited on farmland, or even in the open ocean and the area around them can continue to be used - by cows, fish, and the like.  Similarly, the "land" consumed by PV panels actually may be the roof of a house or office building - not places where one would typically site a nuclear power plant and its supporting infrastructure!

Looking at the consumption side helps to make energy density an even more useful tool for understanding the potential contribution renewables can make.

According to the Energy Saving Trust, electricity consumption in UK households averages 3,300 kWh per year.  (Gas consumption averages 20,500 kWh, but we'll focus on electricity for now.)  With 76 m2 of useable floor area in the average house, this gives us 43 kWh/m2 per year of electricity consumption. UK offices average between 85 and 350 kWh/m2 per year, depending on age and layout.

Of course, we don't consume electricity across every square meter of our homes and offices.  Most of that is used by a handful of power-hungry appliances.  A highly efficient A+ rated fridge-freezer, for example, typically consumes 292 kWh of electricity per year, and takes up 0.25 m2 of floor space - or about 10% of a household's energy consumption on only 0.3% of its floor space.  This gives an energy density of consumption of 973 kWh/m2 per year - almost as high as the production energy density from that old nuclear power station!

These types of calculations help us understand how much space we need to produce and consume electricity in different ways.  It is clear that a refrigerator-sized solar panel will not power a refrigerator over the course of a year, but a house-sized solar array might provide enough electricity to power a house with a refrigerator (assuming it were a one-storey house, the array was properly oriented and one had a battery big enough to store the electricity for use when the sun was not shining).  The rule of thumb in the UK is that you can generate about half your electricity with solar panels on the south-facing half of your roof, which sounds about right for a typical two-storey house.

And under the proper conditions, solar PV just might be enough to power an entire office building, despite the higher energy consumption per square meter. The image below is an artist's conception of Seattle's Bullit Center, an office building that is planned to be energy self-sufficient:

Pretty nifty, isn't it?  As you can see, the solar panels cover significantly more area than the building itself.  From our energy density calculations above, this looks about right.  The building is multi-storey, but designed to be highly energy efficient, so overall electricity consumption might be equivalent to a building of only one or two storeys.  The panels cover a footprint approximately twice that of the building, so from even this initial check we can determine that this scheme might just work.

Making the most of renewable energy, then, is a two-way street.  We can continue to push for technical advances that improve the energy density of power generation systems, through more efficient wind turbine blades, advances in solar cell manufacture, more careful siting to improve the amount of wind or sunlight we can capture and more.

We can also get a better balance between production and consumption by reducing the energy density of our homes, offices and appliances.  In some cases that means redesigning how we use these items so that they require less energy in the first place: bigger windows to reduce lighting bills, deciduous trees on the south facing side of buildings to allow more of the winter sun to strike the building, etc.  In other cases it means increasing efficiency by insulating buildings, switching to less power-hungry appliances, and optimizing their use.

At Carbon Clear, we support the development of ambitious emission reduction targets to combat climate change.  As the discussion above shows, the energy density of cleaner renewable energy sources is sufficient to meet many end users' needs.  Their potential is likely to grow as we continue to pursue energy technology improvements and we drive further efficiency gains where we live, work and play.