Ever since 1970, April 22 has marked Earth Day in the United States. The objective has always been to raise awareness of environmental issues and to prompt individuals to take actions that benefit the environment in some way.
Today marks the first Earth Day of the Obama administration. The President will head to Iowa to promote renewable electricity generation, specifically wind farms. This is part of a larger strategy to gradually wean the US economy off fossil fuels in general and oil in particular. Reducing US dependence on these finite resources is an essential contribution to both climate policy and national security. The administration's energy-cum-green-collar-jobs legislation is already making its way through Congress, albeit slowly.
Of course, any sensible energy policy needs to address not just how electricity is generated but also the total amount used. Without aggressive conservation, renewable electricity - hydro, wind, solar, geothermal, biomass - will always struggle to cover more than a tiny fraction of total demand.
Florida Power & Light has embarked on a $200 million project to install "smart meters" in all homes in Miami-Dade county. Each meter contains a WiFi transceiver that allows consumers to track their electricity usage with software installed on their PC. Knowing when they consume which amount of electricity on a given circuit - mapped to specific rooms or appliances - makes it much easier for them to identify and eliminate power hogs.
California's Bay Area and San Diego are just as exposed to the threat of slowly rising sea levels as south Florida. Yet it is air conditioning demand in the hot inland areas of both states that places enormous strain on the utility companies on the 10 hottest days of the year. In California, aggregate demand can jump by as much as 50% when people return home in the late afternoon and switch on their central A/C unit, often at full power to bring temperatures back down quickly. According to a KQED Quest radio report, simply selecting a device that is optimized for the temperature and humidity range in a particular area can save 20% on A/C-related electricity consumption. There are more than just cost savings here, because the rarely-used power plants that exist purely to cope with extreme peak demand have to deliver that power quickly and reliably - which means using gas turbines. While these could run on stored biogas, the regulatory structure still favors the use of fossil natural gas.
There are plenty of other examples of scope for structural reductions in electricity consumption in California:
- for new buildings, solar architecture encompasses everything from avoiding large south-facing windows to insulation to self-shading, water features and vegetation, all in an effort to keep the indoor and interior courtyard areas naturally cool during the summer months
- in some locations, apartment complexes and businesses can already choose to deploy green roofs with drought-resistant plants supported by recycled water to provide natural insulation
- the pumps used to transport water from the Sierras to Southern California and the Bay Area consume around 2% of the state's total, so encouraging newcomers to move to where the water flows naturally is a good idea - especially since it will also discourage the agriculture of thirsty crops
- Internet data centers in California also consume around 2% of the state's total, of which about half is A/C load. Emerging liquid cooling technology for servers and mass storage units should help bring that down.
Of course, all of the conservation measures described above relate to stationary devices. Small mobile devices like cell phones and laptops, even bicycles, can easily be powered using grid electricity stored in batteries. The same is not true of large vehicles - the high cost, limited range and safety aspects of large battery banks are the reasons why virtually all cars and trucks on the market use internal combustion engines that rely on oil distillates. Commercial airliners rely on kerosene-guzzling jet engines, though when they are fully booked, the newest long-distance aircraft do consume less per passenger-mile than single-occupant cars do on the highway. By contrast, short-hop flights are among the least energy-efficient modes of transportation. That means aggressive conservation and/or switching to electricity is especially important for the transportation sector.
While some bus systems have been electrified using overhead catenaries, it is far more typical of rail transit: streetcars, light rail and subways. In the US, regular heavy rail has been electrified in the NEC but virtually nowhere else. The California bullet train system will be electrified, if only because it's the only way to achieve 220mph. At full capacity, the fully built out network is epxected to require around 480MW of electrical power, roughly 1% of the total installed generating capacity in the state today.
In keeping with the spirit of Earth Day, CHSRA wants it to run entirely on renewable electricity, something that will be easier with energy conservation in stationary applications. In this context, 100% renewable means that for each kWh consumed during a given time period (e.g. 1 year), there must be a corresponding kWh produced at a wind farm or other renewable source. In terms of global warming impact, it isn't strictly necessary that there be sufficient active renewable electricity generating capacity to power all of the trains at any given instant. This arbitrage is exactly where President Obama's smart grid concept comes in, something German scientists have already been working on for a while. For political reasons, that country wants to phase out both nuclear and coal-fired generating capacity.
In the context of a busy rail system, brake energy recuperation from one train to others on the same segment further improves overall energy efficiency, especially if the grid operator gets 20-30 seconds advance warning of a train braking. That information is readily available to the rail infrastructure operator, except in emergency situations.
For all these reasons, I couldn't agree more with this article in today's Des Moines Register, entitled simply:
To push clean energy, back high-speed rail
Even diesel-based "emerging HSR" is a lot more efficient than cars are at comparable occupancy rates. Considering that most cars have just one occupant, that's a low hurdle. Electrification just makes trains an even more strategic element of the passenger transportation mix going forward.
Update by Robert: This seems like a good occasion to remind folks of the CHSRA renewable energy study that we discussed last September. The report goes into detail on just what is necessary for the CHSRA to achieve 100% renewable energy for their system, a goal the Authority's board adopted last fall.