The City of Mountain Iron was awarded a 2017 Seed Grant from the Clean Energy Resource Teams (CERTs) for Renewable Mountain Iron.   The project’s focus is on exploring city wide solar pv potential as well as the potential for on-site solar energy and achieving Net Zero Energy for 9 publicly owned buildings in the City of Mountain Iron.  In addition, the study identified and studied the feasibility of utility scale community solar arrays at 6 sites throughout the City. The City engaged paleBLUEdot llc, a Minnesota Climate and Renewable Energy consultancy to complete this project. 

What, exactly, has the City learned through the Renewable Mountain Iron project?  We were hoping you would ask! 

City Wide Solar Potential
The study looked at the total rooftop generation as well as “optimized” potential throughout the City of Mountain Iron.  The total energy generation represents the reasonably feasible potential for rooftop solar pv generation based on applying solar pv to all available rooftops within the City and the capacity was calculated based on satellite data.  It is appropriate, however, to modify the total generation to reflect the likely total capacity that is reasonably cost efficient installation – that modified generation potential is the “optimized” potential for rooftop solar in Mountain Iron.  The total Optimized Generation Capacity for rooftop solar in Mountain Iron is estimated to be 26,521,520 KWH annually.

The study also explored the potential market absorption – the likely rate of installing solar installations within the City over the coming years.  As an emerging energy sector, there is little data upon which to base projections for likely installation of rooftop solar PV in the private sector.  Additionally, the solar PV market is rapidly changing in both sophistication as well as in pricing and cost effectiveness.  The installed cost of solar PV in Minnesota has dropped 64% since 2012 and is expected to continue to decline in the coming years.  Projections of solar PV installations should anticipate a continued increase in the number of solar pv installations year over year. 

The solar market absorption projections included in the City Wide Solar Potential were based on a number of factors including the solar market history, existing solar utilization, and State-wide market projections.  The resulting market projection anticipates an increase of 635 KW of installed capacity within the City by 2022, equivalent to approximately 1.94% of the total rooftop technical capacity potential or 2.66% of the optimized capacity potential within the City.

Energy Use Efficiency Comparison
Understanding both total electric use and overall energy efficiency of a building are important first steps in prioritizing buildings to receive solar pv.  Initial facility reviews were conducted on the City of Mountain Iron buildings as a part of this planning effort.  This included a review of each facility’s energy use history and the total annual electric use and overall building energy use (including natural gas) was identified, recorded, and reviewed.  The data reviewed and recorded in this report was obtained through the City’s B3 Benchmarking account as well as utility records.

Using 2017 data, the electric consumption of the 9 sites for which data was available totals just over 2,098,601 kilowatt hours annually – or just a bit over 12 kilowatt hours per square foot of building (when the wastewater treatment plant is taken out of these numbers, the average consumption drops to 9.5 kilowatt hours per square foot).  From this review, we know that the Library and Wastewater Treatment plant have higher than the average energy efficiency of their peer groups in the State.  Some of the buildings, like the City Garage/Fire Hall and Senior Citizen’s Center are currently below average energy efficiency.  Conducting a more detailed energy efficiency assessment on the publicly owned buildings may identify opportunities for the City, and School District to increase energy efficiency and cost savings.

Solar Feasibility
We conducted solar feasibility assessments to explore the general potential for solar on each site with the goal of achieving a Zero Net Energy site (a site which generates as much electricity within a year as it consumes within the same timeframe).  These assessments included the development of a detailed solar array design for each building and site.  We also created a detailed computer model of the annual power generation each site would produce – using actual weather data. 

With this modeling complete, we were able to include a 30 year projection of energy production and economic payback for each site.  In all, the 9 sites modeled could produce over 1,612,000 kilowatt hours of power in the first year alone! Five of the buildings may be able to achieve Net Zero status (meaning they generate as much electricity on-site as they consume in a year).  On average, the energy these sites might generate has a value 2 ½ to 3 times the estimated costs to install the arrays…meaning many of these sites could see cost savings by installing solar.

Community / Utility Solar Feasibility
The Study explored the feasibility of developing a utility scale or community scale solar project at 6 sites throughout the City.  These sites are capable of supporting arrays with capacities from 550 KW DC to 10 MW DC.  An array at one of these sites could power from 71 up to nearly 1,400 Mountain Iron area homes.  Based on the efficiency and anticipated performance metrics, the study has ranked each site for prioritization to receive a utility scale array.

Environmental Payback
Increasing use of Solar PV for electricity generation in Mountain Iron public facilities as well as creating a utility scale solar array will offer benefits beyond the economic payback, namely the reduction of Greenhouse Gas emissions (GHG) and the reduction of fresh water use.  Greenhouse gas emissions form, primarily, from the burning of fossil fuels for things like transportation, heating, and generation of electricity.  The generation of electricity also uses significant amounts of fresh water in the extraction of fuels and steam turbines.  For every kilowatt hour used in Mountain Iron, over 5,300 gallons of fresh water is consumed and nearly 1 pound of greenhouse gases are emitted – this is equivalent to over 7 cubic feet of man-made greenhouse gas atmosphere.  In total, the solar potential identified in the Renewable Mountain Iron project represents:

·        420,127,808 kwh of solar electricity generated over 30 years

·        145,000 metric tons of greenhouse gases avoided

·        2,108,000,000 gallons of water conserved

Solar For Your Home or Business
Installing solar panels on your roof is a sound financial decision in almost every state in the nation and Minnesota is no exception!  Many business and home owners are unfamiliar with solar and are unsure exactly how to “go solar” – so here are a few tips:

A key consideration for going solar is often what the economic payback might look like, so exploring payback is a great first step.  Costs and payback can change based on how large of an array you install compared with how much energy you use – so it can help to explore different solar array sizes to find the size array that gives you the best benefit.  Solar pv ownership is typically a great long-term investment, however, out-right purchase of the array may not always be the best option for some – in that instance there are a number of alternative financing and ownership options.  You can find resources for how to explore the solar potential here.