Transmission is the backbone of the bulk electricity system. It facilitates efficient use of a portfolio of resources over vast distances. Sharing resources over wider areas via a robust transmission network reduces the amount of reserves needed to maintain reliability in the case of generator failures or extreme weather. Where needed, transmission adds flexibility to the system, improves reliability, and reduces the cost of balancing supply and demand.

Transmission is particularly important for renewable energy for two reasons. First, generation from solar and wind varies with weather and time of day, but that variability is not correlated over large distances. Wind and solar also tend to have uncorrelated production, with wind blowing more at night. Second, transmission is needed to reach the highest-potential, least-cost renewable resources, which tend to be located in remote areas. A robust expansion of the transmission network is likely needed to realize the benefits of centralized renewable energy.

One of the most difficult parts of getting transmission built is getting permission from states, landowners, and federal agencies. According to the North American Electric Reliability Corporation (NERC), transmission projects require between six and 15 years to engineer, site, permit, and construct, depending highly on the geography, length, and voltage class. But smart planning practices like those outlined by America’s Power Plan can improve the siting and permitting process considerably, which can drastically reduce the lead time for transmission.

To start, smart planning can identify transmission corridors that minimize conflict with environmental and cultural resources, meet future energy needs, and keep capital costs at a minimum, before transmission is actually needed. Ideally, new transmission can take advantage of existing rights of way. In addition, transmission developers can avoid or preempt right of way conflicts by engaging local landowners and respected local leaders ahead of time. Greater coordination between federal, local, and tribal permitting authorities can also help simplify and expedite the siting and permitting processes.

The other key barrier to transmission is fair allocation of benefits and costs across regions. The benefits of new transmission are diverse and substantial and must be taken into account to get valuable projects built. According to Planning for and Investing in Wires from America’s Power Plan, planners should factor in the value of meeting public policy goals (e.g. the Clean Power Plan); linking and consolidating balancing areas; increasing reserve sharing; reducing the total variability of renewable resources, loads, and conventional generators by aggregating larger areas; and accessing higher quality renewable resources.

These benefits of transmission likely accrue to customers in jurisdictions completely removed from the siting, permitting, and planning processes, even if they don’t buy the power directly. In order to get high-value projects financed and built, beneficiaries have to pay their share of the costs. Therefore, it is particularly important to establish regional planning processes that allocate costs equitably between the full range of beneficiaries to ensure that valuable transmission projects get financed and built.