State of the nation

The US is set to adopt renewable energy, but it faces some familiar challenges.

A number of US states are already aggressively adopting renewable energy sources even as (and possibly because) the country's global reputation as a gas-guzzling mega-polluter persists.

As it moves down the renewables path, particularly for solar and wind-based generation, North America is encountering serious implementation issues, particularly at the infrastructural level. No country has tried to adopt these emerging technologies on quite such a scale to date, either by output capacity or by geography. The challenges are compounded by the fact that a number of individual states - from New Hampshire to California - have set tight targets for the percentages of their energy consumption that renewable sources will provide.

Given this framework, the geographical aspect of the US's early experiences with renewables may offer some of the most interesting lessons for foreign observers. With a national grid that has suffered two major blackouts in the last five years - first along the eastern seaboard in 2003 and then in Florida only last February - there are already serious concerns as to how easily new sources of energy can be added effectively. First, we need to get a clearer idea of the scope and scale of the activity that is under way.

Bush-free renewables

You might not guess it from some of the actions and comments of the Bush administration, but the US has kept itself at the forefront of technological developments in renewable energy. Through engineering behemoths like General Electric (GE), it has innovated in terms of wind turbines, while its electronics sector has made consistent contributions to reducing the all-important dollar-per-Watt metric applied to photovoltaics (PV).

But it is not just about the hardware. In 2007, the US became the world's second largest generator of electricity by wind power after Germany, overtaking Spain, and is well on course to take the number one spot within five years. Today, the combined capacity of the five largest wind power states stands at over 10,000MW.

In solar power, 4,000MW of utility scale projects are planned, contracted or under construction using concentrated solar thermal (CST) technology. CST is currently seen as a cheaper generation technology than PV. However, PV is thought likely to become more cost effective as it takes greater advantage of semiconductor-based cost-down economics.

One can also boil this activity down into individual projects with powerful backers. Earlier this month, T Boone Perkins, once one of the US's leading independent oilmen, announced that his Mesa Power venture has placed a $2bn order with GE for 667 turbines. They will generate 1,000MW and comprise just one quarter of Perkins' Pampa Wind Project in the Texas Panhandle.

"You find with an oilfield, it peaks and starts declining, and you've got to find another one to replace it," says Pickens. "It can drive you crazy. With wind, there's no decline curve."

Meanwhile, in late March California governor Arnold Schwarzenegger announced two projects that will deliver a combined 500MW from solar sources for his state. Half of this will come from one of the world's largest ever roof installations of PV panels, covering 65 million square feet of commercial buildings and overseen by utility, Southern Cal-Edison.

California is among those US states with aggressive renewables targets - one of which is securing 20 per cent of its electricity from such sources by 2010. However, Schwarzenegger, who has emerged as one of the US's most technology savvy politicians, wants more.

"California has the power, we have the innovation and we have the will to make this an energy independent state, to make it the first state in the union to be energy independent while we are fighting global warming," he told the solar launch press conference. "Now it's not going to happen overnight, but deep down in my heart I know it will happen."

From A to B

It is generally accepted that for a utility-scale, single-site renewables installation, you are most likely to choose a remote location. You need a lot of land (Pampa Wind will ultimately cover 400,000 acres, for example). You also tend to find that the locations with the best potential are the less hospitable (desert land in Arizona and Nevada for solar sites, for example). And nobody wants these things in their back yard.

This mix of issues tends to mean that sites for energy generation are likely to be comparatively distant from the places where there is greatest demand, particularly urban centres.

It costs roughly $1.5m to build out a mile of high-voltage transmission line, and the responsibility for this will typically fall with the local energy utility. That company is not necessarily the one building the actual wind or solar installation. So, there is an immediate question - some would say squabble - over who assumes the risk for carrying the power to the people.

A second point concerns the time taken to realise each part of such a project. Today, a wind or solar farm can be built quickly. Pampa Wind is a useful example. Perkins says that he can have the project operating at its full projected capacity of 4,000MW and providing service to 1.3 million homes by 2014, even though he has only put in an order for 25 per cent of this vision so far. Stage one is likely to take only 18 months.

By contrast, the construction time for transmission lines can reach five years or more. This process includes securing necessary regulatory approval, an issue that, for American projects, can involve the federal government and potentially a number of state-level authorities depending on how far the power will have to travel.

Finally, remember that there is increasing concern over the integrity of the US national grid itself. The North American Electric Reliability Corporation (NERC) is an industry body that oversees the health of the grid, producing quarterly and annual reports that assess its state at varying levels of granularity.

NERC's last major technical report was published in September 2007, based on a survey of professionals operating in the transmission and distribution (T&D) business. When asked what they thought were the 'high risk' sources of a major grid breakdown, the top three threats cited were "aging infrastructure and limited new construction", "transmission system congestion", and "operating close to load limits".

All are pretty clear variations on the same theme, each was cited by more than half the respondents, and no other class of risk came close to these. All these observations also came before last February's Florida blackout. ESL - the electrical system-level

The US has decided to give itself the option of brute force if it cannot resolve the various tensions within the transmission problem.

The Energy Policy Act of 2005 gave the Federal Energy Regulatory Commission (FERC) backstop signing authority over the siting of transmission lines.

These powers - which, importantly, have yet to be used in anger - will be exercised in the context of two National Interest Electric Transmission Corridors that have been identified by the US Department of Energy. These corridors - many miles wide - run through the country's eastern industrial heartland, and on the west coast cover an area based around Los Angeles, California and the prime generation land near Phoenix, Arizona.

In short, Washington has decided that if the states cannot resolve these issues among themselves, then it must. However, before it can, a lot has to happen and that can take a lot of time.

"The process still requires a lot of upfront conversations to take place before someone comes in and draws a line on a map. That's always the tricky part of any transmission undertaking," explains Katherine Gensler, manager of regulatory and legislative affairs at the Solar Energy Industry Association.

"First, there is a lot of upfront process work with stakeholders. They've modelled it on what the hydropower relay system side of things does, where they have a very inclusive process and you get a lot of voices in the conversation early before moving too far down the path, certainly before you get to approval or construction."

As a result, most of the 4,000MW of CST projects identified by her association are being developed on the basis that they can use existing infrastructure. Indeed, while there is a debate running in the background about new transmission build out, the technological emphasis is falling on exploiting existing resources as far as possible, despite NERC's concerns.

"It's not just about putting new wire up. It's about making better use of the assets that we have, about using the rights of way that we're given in a more effective manner, and other similar things," says Gil Bindewald, acting deputy assistant secretary for R&D at the US Department of Energy.

He certainly backs work on higher capacity conductors and various other new technologies: "Anything that streamlines and optimizes the existing system. From an R&D standpoint, we are looking a lot at energy storage, power electronics, smart grid technologies. The important thing, though, is that we're really trying to address this as a system, holistically from generation to end-user.

"The number one goal in that respect is having the wide area visualisation and monitoring and testing of the system. It is about working on safer measurement units, and effecting technologies to understand the state, the health of the system. That requires a real-time platform for wide area monitoring of the grid."

Meanwhile, attempts to upgrade existing infrastructure are likely to run alongside distributed R&D as well as storage models. "With solar, one of the more flexible aspects is that you do have multiple models to play with."

In effect, the US is creating a huge test-bed, looking at how to fit renewables into an energy system at multiple levels. Will it work? Perfectly - almost certainly not, and all the players are braced for a rapid ascent up a very sensitive learning curve.

But given the factors at play - and the increasing availability of capital and investment - it now seems likely that this is where more broadly applicable models will be taken to the next level.

Certainly, the threat of a bottleneck is also clear. To offer one final example, wind projects alone that could have a capacity of more than 22,000MW have been tabled in Minnesota, according to one report.

What is beyond doubt, though, is that current plans to extend the states transmission capacity reach to only 2,000MW.

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