The Grid of the Future is More Than Just Smart
Much of current conversations about energy grids in the US revolve around smart grid technology and the integration of renewables, but think bigger and further: 2050. What about a grid that is truly integrated across electric, thermal, and transport energy and relies on 100 percent renewable energy? A 2012 study from the Fraunhofer Institute for Solar Energy Systems took a close look at this concept, concluding that there are multiple options that would result in operational costs that are less or only marginally more than today. A look at this research is timely considering the recent release of Minnesota’s energy futures scoping report study, offering guidance to how the state might approach further investigation of a clean energy future.
So how is this possible? While the cost of such infrastructure conversion is not discussed in the analysis, the system tests the 100% renewables scenario with no electricity imports. Not only does it find that this scenario is highly feasible, but when a maximum imports scenario was tested, just 2% of electricity would be imported, covering only the most extreme peaks in demand. Ground source heat-pumps, solar, and biomass were the primary heating energy sources. On the electricity side, a broad array of technologies were used, but the resource portfolio maximized on-site and off-site wind, and ramped up greatly on solar, biomass, and hydrogen.
Power-to-gas plants and cogeneration plants would play a major role in the system, as nodes of efficient energy production and conversion.
One of the big shifts under this paradigm is the greater reliance on the natural gas/methane grid. Methane would become the heating energy of choice, not only because of its naturally occurring prevalence and production from biomass, but it can also be created from water and carbon dioxide using wind and solar energy. Thus, natural gas from renewable energy would not only leverage existing infrastructure for storage and transportation, but it can bridge the transition from fossil fuels to clean energy. It, along with pumped hydro storage, would become the primary vehicles for storing renewable energy for extended periods of time. The inherent flexibility and reliability benefits of holding and distributing energy in the form of gas are obvious – that energy can be saved and used at the best possible time and place.
At the same time, the electric grid would become more relevant as vehicles move into a new era of fuel sources. The IES study did not speculate as to which vehicle fuel sources would gain the greatest market penetration, but electric motors convert energy at an efficiency of more than 90% compared to the 25% for combustion engines. The flexibility of this system would lend itself to the shifting loads coming online from vehicles and offer operators more tools for balancing demand and supply. This visionary grid would be cleaner and more efficient and help match loads with the most efficient form of energy.
So what does this look like from the consumer side?
Perhaps on a windy day in North Dakota, excess wind-generated electricity might be converted to methane and transported via pipeline to Georgia. Here it would be converted back to electricity and heat in a combined heat and power (CHP) plant. Renewable electricity would power the local electric grid, in say Savannah (because that day there isn’t enough Georgia sun), while renewable heat is used for nearby industrial processes or saved as a thermal sink for future heating loads.
Or maybe a natural gas/electric hybrid vehicle is charged by excess solar energy in California and driven to Colorado, refueled with renewable natural gas along the way. The natural gas would recharge the car battery, which is plugged in at home in Colorado, connecting to the local grid and balancing evening fluctuations in the electrical grid from diminished solar power generation late in the day.
Current electricity transmission systems transport energy with about 7 percent in line losses. Transport loses for natural gas via pipeline are about 3 percent.
Of course an energy system transformation such as this would require substantial adjustments to policies and processes that govern and safeguard the system. The different levels at which authority is held for pipeline and transmission line planning and siting add layers of complexity. The same would be true as to the reliability and security considerations that would be at play.
Grappling with the magnitude of investment is another question. A 2011 Brattle Group report looking at the cost of making the grid ‘smart’ estimated costs of $240 to $320 billion over the next 20 years. This does not get at other capital costs needed for a smarter system, such as the development of new renewable generation equipment, new cogeneration facilities, and additional storage integration. Interestingly, the IES model highlighted the continued role of energy efficiency. Future heating loads are modeled to be 35 to 50 percent lower than those in 2010. This means that an important fraction of the cost to reposition our infrastructure comes from investments in the efficiency of our buildings.
These are some serious costs, but instead of what? If serious action isn’t taken to slow the negative environmental impacts of our energy and transportation economy, we will be looking at costs 100 times the magnitude. Power outages alone, stressed by climate change are currently costing $100 to $180 billion per year (direct and indirect costs) while direct damage costs from recent natural disasters range from $2 to $6.5 billion per event. Instead, an overhaul of this size is estimated to supply 130,000 jobs or more each year (US Chamber of Commerce Report, 2011) and reduce sensitivity to an increasingly more extreme climate, geopolitical events, and diminishing natural resources.
While the ‘smart grid’ promises to usher in an enhanced electrical grid, the smarter grid may offer these benefits to all fuel and grid types, across geographical scales, and with long production and consumption periods. Grid operations for such a system might look significantly different than they do today, but perhaps this model is a worthy trajectory to be considered, particularly as the state looks at possible clean energy pathways. We are finally standing at an innovation edge that allows us to not only see the benefits of individual technologies, but the infrastructure synergies that we need in a cost-effective future.
Image credit: Robert S. Donova and Duke Energy via Creative Commons