Transforming sun's energy into savings on electric bills

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By Sandy Barnes

An array of 40 photovoltaic panels strategically placed in the yard of Mike and Joan Spalding’s home in Kerr Gulch is generating enough electrical power to keep them warm and take a huge chunk out of their utility payments.

Hank Kaanta of Evergreen Sun Power, who oversaw the installation of the 10-kilowatt solar electric system, estimates that it will produce an average of 15,000 kilowatt-hours (kWh) a year, or 1,250 kWh a month. 

“Because the Spaldings will produce most of their own electricity, Xcel will be receiving a much smaller monthly check,” said Kaanta. Also, because the Xcel rebate program actually pays them for all the electricity they produced, the Spaldings expect to receive a monthly check from Xcel for about $112 a month for the next 10 years, Kaanta added.

In addition to monthly savings on electric usage, the Spaldings are eligible for a 30 percent federal tax credit for the cost of the installation.

The average cost of a residential PV panel array is $20,000, said Kaanta. The expense of the installation varies according to the location of the system and weather factors at the site. An engineer works with Evergreen Sun Power to design the array, taking into account the amount of snow and wind it will need to withstand. 

Placement of the array is critical to optimize the amount of sun the panels absorb between 9 a.m. and 3 p.m. When designing a system, a device is used that shows how shadows fall on the property, said Kaanta.

At the Spaldings’ home, there are many trees that can shade the panels. To make sure the Spaldings’ array would have sufficient sunlight, a few trees were relocated. This wasn’t too hard a task for Mike Spalding, who has a tree and landscaping business and the equipment to dig up and replant trees as tall as 30 feet.

Another consideration for the Spalding project was that the couple already had an existing solar power system on the side of their home.

Mike Spalding installed an active air solar system in the early 1970s when he and Joan built the home. The thick walls on the side of the house are covered with sheet metal and glass panels, which draw in sunlight. This system uses a fan to pump and circulate warmed air throughout the house. 

Because of the amount of electricity the home uses with its electrical heating system, the Spaldings recently decided to add the solar array for additional savings.

“We look at it as an investment,” Mike Spalding said. “We want to produce as much as we could from this system.”

With this tax credit and Xcel rebates, Kaanta said the Spaldings’ solar electric system should pay for itself in less than seven years. Afterward, the system should provide free amounts of electricity for the next 30 to 40 years, he added.

The PV panels have a 25-year limited warranty, but can last much longer, said Kaanta.

“We use products made in Germany, Japan and North America,” he said. “The guarantee is good.”

Kaante also said that solar arrays have become more affordable than they once were because of their increasing popularity and the availability of PV panels.

How the system works

“No batteries are required … There are no moving parts,” Kaanta said while explaining how the solar electric system operates.

The PV panels are made with silicone and aluminum, which collect sunlight and convert it into direct-current electrical power. An inverter installed on the house then makes a DC-to-AC conversion so that the electrical power from the PV panels can be used.

The net meter keeps track of the electrical energy the PV panels generate each month. 

Because electrical energy cannot be stored, the PV system only works when it is receiving sunlight. In off-the-grid systems, large batteries are used to store electrical power generated. However, with systems such as the one that the Spaldings have, Xcel continues providing electrical power when there is no sun.

While some PV panels are made with rare earth elements mined in China, the type that Evergreen Sun Power uses in residential installations is silicon-based.

Kaanta also noted that PV panels perform better in cooler environments in higher altitudes such as those found in Evergreen.