When considering the steps necessary to add a rooftop solar installation, the list can sometimes surprise people. Between permits and tax rebates, to say nothing of the actual installation, the process is not without its difficulties. Some solar installers recommend replacing the roof beforehand as well. But what surprises some people the most is that even their electricity meter must be replaced.
While photovoltaic solar panels provide many benefits to homeowners, constant production upon command is not one of them. Without a substantial battery system, houses with residential solar installations must still be tied into the grid in order to have access to power when it is needed.
Particularly in homes where the owners are off at work during the day, most of the electricity these solar panels actually produce gets put into the grid and used by houses and businesses nearby.
But traditional electricity meters are relatively simple devices. They track the flow of power into a house steadily upward and must be checked by someone from the utility company to find even this information. The idea of tracking the flow of electricity from the grid into a house as well as from the house back into the grid was never a concern when most homes were first built. But in order for homeowners to be credited for the energy they produce, and often to benefit from it at all, utilities must be able to track it.
This is where smart meters come into play. Some earlier smart meters are limited largely to tracking electrical flows in two directions, but most provide a substantial upgrade over traditional meters because they provide a wide array of other information as well. These systems also provide an automatic cut-off during outages to prevent electricity from flowing back into the grid when power lines are being worked on.
The high degree of information coming from smart meters has led many to support the idea of smart grids, wherein entire networks of these meters are used to track electrical demand across the region. With greater adoption of solar electricity, such a system could also serve to track the amount of energy input back into the grid, helping to tailor production at central power plants.
Many hope this kind of information could lead to improved efficiency as well as fewer and more quickly resolved outages. However, a full-fledged smart grid could allow for readier adoption of home solar installations, not only by removing a step from the process but by helping to establish systems that are favorable to distributed power generation.
Some smart meters have been used to vary the price of electricity based on the time of use, with higher prices during the day when demand is at its peak. And also when solar production is at its peak. Particularly for homes that use electricity at night when demand is low and produce it when demand is high, this could provide even more substantial financial incentives for homeowners to invest in solar.
Solar does pose some problems for the smart grid, however. GreentechMedia notes that the intermittent nature of solar power could cause complications in balancing supply and demand in areas with a heavy concentration of solar. Systems will need to be put into place to ensure that traditional power generation can pick up the slack when cloud cover rolls in.
Many communities have been wary of investing in widespread smart grids as well because of the potentially high cost - smart meters generally cost several hundred dollars each for thousands of residents. However, just as options such as solar leasing have emerged for homeowners, General Electric has introduced smart grids as a service, charging a monthly price both to install the smart meters and to host the data it collects.