Considerations for Remote Systems

The economics of remote wind systems are different than grid-connected systems, for several reasons. One is that a decision has to be made to either install an independent energy system or to pay to have the power line extended to your location. As a rule of -thumb, it is probably cost-effective to install a wind system to meet the energy needs of a small, remote load (e.g., residence, water pump) if the power line is more than a half-mile away and the site has an average hub-height wind speed of at least 12 mph. However, for an energy intensive application, such as a business or factory, a line extension may be justified.

Another reason for the difference between remote and grid-connected system economics is that there are many types of independent energy and storage technologies available to choose from, with wind energy being just one. They can be used exclusively or combined into hybrid systems.

A third reason is that the selection and sizing of your system components is critical to energy supply dependability. An intermittent power application like water pumping has different design criteria than a home or communication repeater station where electric needs are more continuous. These issues are very user- and site-specific, thus making the discussion of remote system economics non-generic.

The cost to extend an electric utility line is a function of many factors:

  • The particular utility company
  • Distance from the utility
  • The terrain and ground cover along the line extension route
  • The need to obtain rights of way from affected land owners along this route.
  • Zoning regulations that control the use of overhead versus underground lines
  • The line capacity.

Similar to a grid-connected system, a remote system has initial and lifetime operating costs. Initial costs will include equipment components such as batteries, controls and an inverter to supply AC loads. In addition to servicing, maintenance and insurance, annual operating costs will include battery replacement every 3 to 10 years, depending on the battery type and the number of discharges.

The cost effectiveness of a wind system relative to a solar electric (photovoltaic) or propane generator cannot be determined solely by comparing the initial and annual operating costs. This is because these systems rely on different fuels that are available at different times. For example, a solar system without a battery can’t work at night. The availability of energy output from these systems must be compared to the time periods when energy is needed, both on a daily and seasonal basis. Battery systems can store excess energy for use when your energy system is not operating. However, the size and cost of the battery system depends on the degree of match or mismatch between when energy is produced and when it is used. It is economically beneficial to minimize battery size by properly matching the wind resource availability with load requirement. Therefore a careful analysis of your energy needs is essential to design an optimal remote energy system. Remote system dealers and installers can assist you in developing an appropriate system design.