Proposed Solutions

In a survey conducted in fall of 2018, we found that 60% of all light bulbs in homes in Stehekin were incandescent lamps. These bulbs use up to 90% more energy than an LED bulb. Since 2018, the PUD has replaced over 3,000 incandescent bulbs in Stehekin. This is a very cost-effective way to save energy in homes in Stehekin.

The PUD is investigating battery energy storage systems for Stehekin that would run in parallel with the plant’s existing hydro and diesel generators. The proposed system would have the ability to provide up to 250 kW of additional capacity.

The battery would be designed to provide additional power whenever the Stehekin loads exceeded the capacity of the hydro system, or if the hydro system is shut down for short periods for maintenance. It would be recharged whenever the loads dropped below the output of the hydropower generator output.

The battery energy storage system is estimated to cost approximately $350,000. The PUD is eligible to receive a $125,000 grant from American Public Power Association to help pay for the battery. If approved by the board, the battery system would be installed and operating in 2021. 

Phase 1 conservation would include lower-cost solutions. Examples include commercial lighting replacement to LED, replacing electric heat water heaters with heat pump water heaters, replacing pre-1993 refrigerators/freezers, commercial ductless heat pumps, and commercial and residential insulation and weatherization.

Chelan County PUD offers rebates on some energy efficient upgrades, and would advise customers on these opportunities.

This measure would use radio frequency-controlled relay switches to remotely disconnect electric water heaters temporarily until system peak loads drop. Right now, the annual software and maintenance costs were found to be too expensive for the relatively small number of water heaters in Stehekin. If this measure were implemented, it would not be until the future when a less expensive water heater controller can be located.

Phase 2 conservation would include higher-cost solutions. Examples include residential ductless heat pump replacements, residential window replacement, and replacing pre-2000 refrigerators/freezers.  

Chelan County PUD offers rebates on some energy efficient upgrades, and would advise customers on these opportunities.

With this proposed measure, the PUD would provide propane clothes dryers, stoves and ovens, and water heaters to replace existing electrical appliances. In addition to replacing the appliances, for those customers who do not have propane, additional costs would be needed to provide propane tanks and propane piping. The cost effectiveness of this measure does not include the additional cost of propane for the customer. At $2.50 per gallon, using propane would cost the equivalent of $0.10 per kWh.

Installing a large solar array of approximately 200 kW near an open field, such as the airport, could help reduce the need to run the supplemental (D2) generator during the spring, summer and fall months. However, the solar photovoltaic system would not reduce winter, early morning or late evening peak loads.

The existing hydro generator has a single nozzle Pelton wheel. The existing system runs at relatively low efficiency because the diameter of the water jet is relatively large compared to the diameter of the Pelton wheel.

Increasing the number of jets would result in smaller jet diameters, which will increase the amount of energy that can be generated from the same flow of water. The additional jet has been calculated to increase the hydro generator’s nominal output from 180 kW to 220 kW.

This capital improvement would be the most expensive solution.