Generating Clean Solar Electricity for your Home in New Hampshire
With no moving parts anywhere in the entire system, grid-tied photovoltaic (PV) systems are the most reliable renewable energy technology available. This is why PV manufacturers warranty their panels for 25 years, while the expected useful lifespan of PV panels is closer to 40 years. Producing your own clean, renewable solar electricity for decades is a great way to lock in your electricity rate and transition away from the massive CO2 emissions that come from America’s coal and gas-fired power plants. PV technology has been in use for more than 60 years, which means that today’s systems are highly evolved, reliable and efficient. Locally produced solar electricity eliminates the huge amounts of energy wasted through inefficient long-distance transmission of electricity over the utility grid.
What does Grid-Tied mean?
Battery-based solar electric systems were common until the grid-tied inverter was developed. Modern inverter technology eliminates the cost, complexity and toxicity associated with lead-acid battery storage systems. Rather than connecting solar panels to a battery bank, the panels are connected directly to the inverter, which feeds clean electricity into the building’s electrical system and/or the local utility grid. The inverter allows your solar electric system to feed surplus solar power to the grid, or seamlessly draw electricity from the grid when there is not enough sunshine to meet your demand. During the summer months, when you are likely to be producing more than you need, the surplus feeds your neighbor’s demand and you get a credit on your bill from the utility.
Under New Hampshire’s net-metering law, your local utility typically upgrades the meter at your home or business when your solar electric system is installed. The new meter records both the electricity that you export to the grid and the electricity imported from the grid. Each month the utility will reconcile the two meters and either bill your account or credit your account accordingly. Some utilities, such as New Hampshire electric co-op, may allow solar PV systems to interconnect even when they have exceeded their mandated state cap, but offer terms less financially advantageous as retail net metering.
How it Works
Solar electric panels are typically mounted on a south-facing roof section, but can also be install on the ground using poles, racking built into the ground, or sun trackers when the roof is not a viable option. Major system components include the PV panels, wire and conduit, and the inverter.
When sunshine falls on the PV panels, direct current (DC) electricity is generated and flows through a wire to the inverter. The inverter converts the DC electricity to alternating current (AC), which is the type required by your home appliances. The AC electricity flows from the inverter through a wire into your electric panel. The solar electricity will then flow through your electric panel and satisfy any household demand. If your solar electric system is producing more than the demand in your home, the surplus will then flow out through your ‘export’ electric meter and travel against the normal flow of electricity through the utility line serving your home and back out onto the grid, looking for the next closest demand.
Integrating with Battery Storage
Most solar energy systems being installed these days are totally grid-integrated, meaning they are dependent on the electric grid and when the grid goes out, they shut down (so as not to backfeed and electrocute workers repairing power lines).
However, thanks to advances in battery technology, grid-tied solar PV customers are finding it increasingly affordable to add on a battery backup storage component, which offers a number of compelling features:
- Backup power in utility outages without the burning of fossil fuels / using a generator
- Self consumption – use the day’s solar harvest at night, reducing a system’s dependence on the utility grid, and thus also decrease reliance on Net Energy Metering
- Reduce demand charges by using solar + storage to reduce your power needs during peak daylight hours