Solar Array Installation

IEA has an interest in alternative energy sources, such projects can be a valuable addition to its portfolio of assets, and believes there is a large untapped market for services related to alternative energy.

In order to gain expertise in this area, three of IEA’s staff members completed a comprehensive training seminar put on by the Midwest Renewable Energy Association. The topic of this seminar was Photovoltaic Systems; Design and Installation.

There are a substantial number of design questions to consider when installing such a system.

• Which nearby trees, utility poles and lines, signs and other obstructions might adversely impact performance of the system?

• What is the optimal angle to install a fixed solar module at your latitude?

• Do you need special permission from your local electrical utility to install such a system, even if “behind the meter?”

  • (The answer is generally, Yes.)

• What are the interconnect requirements of your local electrical utility?

• What are the benefits of tracking PV systems?

• Should I use batteries to store energy generated by a PV system?

IEA then put this knowledge to work by purchasing and installing a nominal 3,000 watt solar voltaic system on the roof of its Marion Diesel Substation. The system consisted of 12 solar modules rated at 240 watts coupled with individual AC inverters mounted with each module. This method eliminates the need for a costly central inverter and the complex wiring associated with such a system.

An Interconnect Agreement was reached with the local electrical utility, and a bidirectional utility meter was installed. This system will not provide all the power requirements of our building, but with the “net metering” arrangement we have with the utility, we are able to utilize the solar power during the more expensive daytime hours while relying on the utility system during cheaper night time hours.

The site was already on a Time of Day metering system with our utility supplier. On this program, electric energy consumed at off-peak hours, nights, and weekends, is billed at a 40% discount to normal tariff rates. However, energy consumed during the daytime hours is billed at a 40% penalty to normal rates. This particular location houses four of IEA’s diesel generators and is normally not staffed. Since the primary use of electricity at this location is to power the jacket water heaters for the engines, these heaters have been placed on timers to operate them primarily during off-peak hours.

The solar power installation obviously generates its energy during daylight hours, when little energy is being consumed in our building. Since a considerable amount of energy is needed at night to power the engine jacket water heaters, we are able to utilize our net-metered solar power at night. This arrangement has worked out very well. Thus far, this system according to the manufacturer, represents a reduction of 4,000 pounds of carbon emissions to the environment.

This system also has the ability to report back to a website, where real-time and historic performance characteristics can be monitored.