Diesel/solar hybrid power system — Is it a viable option for telecom applications in the Arctic?

Northwestel is a Canadian based telecommunication company that currently operates over 100 “prime powered” sites supporting a microwave radio and fiber optic based telecommunication network. This network is located in some of the most rugged and sparsely populated geography on the planet, encompasses 3.9 million square kilometers of Canada's North, including the Yukon Territory, Northwest Territories, Nunavut, and Northern British Columbia. The operation and maintenance of the network repeater sites involves significant resources and expenses due to their remoteness. Access to approx 40% of the sites for quarterly maintenance and fuel delivery is via helicopter, which is very costly. Small scale 10-15 kW diesel generators, along with battery storage, is the system of choice for providing our “off grid” power requirements. This arrangement has provided the remote site energy needs for many years, while assuring an incredibly high level of reliability. However, given the financial realities of the Telecommunications industry today, with increased competition and shrinking margins, the need to reduce operating expenses is driving the search for innovative methods to produce power in a more cost effective manner. The price of photovoltaic (PV) equipment has been greatly reduced in recent years, sparking the question of its potential use in Arctic regions. Integrating PV into Telecom power systems is nothing new, but is it practical in the Arctic, both technically and financially, given the dramatic variability of available solar resource, frigid temperatures, and ice & snow through a large part of the year? In 2012, Northwestel partnered with Yukon's “Energy Solutions Center” and “Cold Climate Innovation Center” in a research project to test the viability of adding PV to an existing diesel powered site near the Arctic Circle, with the objective of determining the technical and financial viability of a Diesel/PV hybrid system. In 2013, a 15 kW PV system was installed at an existing mountain top microwave radio repeater site, along with data collection equipment to monitor energy production and site conditions. This paper describes the Diesel/PV system installed, compares the “energy model” to “actual energy produced”, discusses technical issues faced in the harsh Arctic environment, and reviews the viability of the business case based on the Capital cost of the system relative to the savings achieved through reduced diesel consumption (if any).