How Solar Electric Systems Work: Technical and Logistical
How do solar electric systems work – Technical
1. Solar Modules
Solar panels are installed on the roof, ground, parking structure or any other adjacent structure. The panels are made up of photovoltaic cells which convert sunlight into direct current (DC) power.
2. Inverter
The DC power created by the photovoltaic modules flows to an inverter (power converter), where it is converted into alternating current (AC) power – which is standard residential and commercial electricity.
3. Electrical Meter and Distribution Panel
The AC power flows from the inverter to the main electrical service panel, and then the power is distributed through your business or organization. The utility meter then measures the electrical supply: If your solar system produces more power than you need, the meter spins backwards and the excess power is exported to the grid. This exported power then generates a credit with the utility company.
4. Utility Grid
The utility grid supplies you with electricity when you need more power than your system produces. You will normally be using power from the utility grid at night when there is no sunlight. Any surplus power generated by your solar system flows back into the grid. Once you have installed a solar power system, you and your utility company will enter into an ‘interconnection’ agreement, also termed ‘Net Metering.’ This states that the utility will credit your account for any excess electricity that your solar power system generates.
Time-of-Use (TOU) Rate Plan
Many utilities offer “time-of-use” (TOU) based rate schedules. Rates vary depending on the time of day, the day of the week and the season. Peak rate periods are typically weekday summer afternoons (which is also peak production time for a solar system). If you generate excess solar power during these peak hours, you will sell it at the highest rate. And during evening hours, when your system is not generating solar-based power, you will buy electricity from the grid at lower rates.
How do solar electric systems work – Logistical
As solar integrators we have a simple 4 step process to determine feasibility for your unique site and financial requirements.
1. View Property on Google Earth
- Initial study of property layout, structure orientation, shading, etc.
2. Request Electrical Bills
- Analyze consumption and demand patterns and rate structures over a 12 month period to determine usage, peak loads, demand charges and price paid per kWh
3. Site Survey
- Take on-site measurements
- Examine existing electrical system
- Examine property conditions (roof, etc.)
4. Solar Opportunity Analysis
- Solar Overview and Incentives
- Preliminary System Design – based on usage and site characteristics
- Potential Power Production Output
- Cost-Estimate Per Watt
- Proposed PV System Investment
Once contract is established, SunGreen Systems will deliver a turnkey solution. Our scope of work is listed below:
1. Size System: PV System Sizing and Performance.
2. Design: Module layout and design, inverter placement.
3. Reserve Rebate: Apply for solar rebate from local utility company.
4. Permitting:
a. Prepare submittal package with architectural, electrical and structural drawings.
b. Obtain local agency permit for installation.
5. Racking Install: Install supporting solar structure on rooftop or specific location.
6. Panel Mount: Mount solar panels and electrical works.
7. Inverter Install: Install solar inverter with DC and AC disconnects.
8. Electrical: Wire entire system and performance check.
9. Inspection-City: Obtain final sign off from local agency.
10. Commissioning: Final commissioning with local utility company.
11. Inspection-3rd Party: Arrange for third party inspection for the solar system if required by the local utility company.
12. Monitoring: Install system monitoring software and hardware.
13. Owner’s Manual: Create and deliver a system specific owner’s manual.
14. Owner Education: Familiarize owner with system details.
15. SGS Ongoing Monitoring: Remotely monitor system from our headquarters in Irwindale to insure optimal system performance.
