Microgrid feasibility study secures $26M grant for eight Alaskan villages. Here’s how they did it.
Remote communities in Alaska that rely on diesel-fired generators are a great application for microgrids that incorporate renewable energy resources. Proving a microgrid’s feasibility in the region, and earning grant money to implement such a project, is not so simple.
The Tanana Chiefs Conference (TCC), a tribal consortium in Interior Alaska serving 42 communities, had a goal of incorporating solar PV arrays and battery storage systems into existing microgrids at eight communities in its territory. And *spoiler alert* the TCC received a $26 million grant from the U.S. Department of Energy’s Office of Clean Energy Demonstrations Energy Improvements for Rural and Remote Areas (ERA).
According to Eddie Dellamary, Rural Energy Specialist for the TCC, doing the feasibility study early in the process helped them earn the grant.
“This feasibility study really unlocked what were our possibilities, and I would say really gave the funding agency, the granting officers at the Department of Energy, the confidence in us that we had gone to the experts in this field for that feasibility study,” he says.
By tying in solar + storage, these communities are seeking energy sovereignty (renewable energy vs. relying on shipments), lower energy costs, and less air and noise pollution. The feasibility study and preliminary engineering to support that grant application was produced by Mayfield Renewables. Mayfield Renewables used Xendee’s DESIGN microgrid modeling software, which streamlines Distributed Energy Resources (DER) modeling process while creating detailed financial and technical reports.
The details of the project and the microgrid feasibility study were explained in the Transformative Power of Microgrids webinar on June 20, part of the Dispatches from the Energy Transition series produced by Mayfield Renewables and renewable energy marketing agency Outfit. The next Dispatches webinar is set for July 25, covering a microgrid project for the Calistoga Boys and Girls Club.
This webinar explained the feasibility study process, demonstrated the importance of simplifying microgrid complexity, and showed the impact of locally produced clean energy for the Tanana Chiefs Conference. So, how did they do it? Watch the full webinar below, or scroll through our takeaways.
Four Steps of a Microgrid Feasibility Study
1. Establish Baselines.
“The goal is just determining what are your constraints, and then adjusting for them,” explains Lucas Miller, senior engineering consultant at Mayfield Renewables. Mayfield starts with a purpose analysis to understand goals and constraints from the project’s outset, asking questions like:
- Understand the site as is. What are the loads? This starts with initial data collection — often involving a full one-month load study, but pulling utility data could do the trick if available.
- How is the facility or the community using its electricity?
- Is there a budget with a hard cap to what we can spend?
- What loads would you want to prioritize backing up if we’re unable to back up all of them?
- How much land do you have available to install a PV array?
Looking at the TCC projects, the Nulato, Huslia, Minto, Kaltag, Grayling, Anvik, Shageluk, and Holy Cross communities have relied 100% on expensive air-lifted diesel fuel. And like more than 90% of the TCC communities, several are off the road system. “Meaning that you cannot drive to them,” Dellamary says. “They are incredibly remote.”
These islanded microgrids are powered primarily off diesel power generation. Loads on average in these communities vary between 10 to 400 kW, with an average of 100 to 120 kW loads. Luckily, the local utility is an Electric Cooperative that was able to provide Mayfield data going back to the 1990s.
Imagine the difficulties of transporting liquid fuel to each of these communities — primarily by barge, some by road, some via small bush planes. Those buying in bulk see prices in the high $3 per gallon.
“But the communities that have to fly in fuel it ranges from anywhere from $6 to $15 a gallon,” Dellamary says, also noting:
- Dollar per kWh can be three to five times the national average.
- Fuel comprises 50% or more of that price per kWh.
Hear Dellamary explain one particularly treacherous fuel delivery location (especially considering the fuel is needed most when weather is the worst):
It goes without saying the impact of investing in locally generated renewable energy will have in terms of cost and emissions reductions. The feasibility study shows the renewable energy microgrids will contribute to a 40% reduction in diesel consumption during summer months.
“At the end of the day, the rate payers in these small communities are put in this burdensome position where they’re paying hundreds of dollars per month,” Dellamary says. “A community of 60 people paying three to five times the national price of electricity in some of the poorest communities in America.”
2. Energy Modeling + Financial Modeling + Prelim Designs
The modeling phase involves energy modeling, financial modeling, and technical analysis done via engineers. Mayfield relied on Xendee’s feasibility tool for this project, which does both energy modeling and financial modeling. For this project, the financial analysis is focused on diesel savings, but in other projects it could be avoiding peak demand charges.
Mayfield engineers used those energy and financial models throughout the process to build a preliminary design set for the TCC.
“We call that roughly a 30% set; something you could take to your grant application or even to a utility just to have them better understand the goal for the system,” Miller says. “It’s not 100% ready but based on modeling and analysis this is what we think is feasible, and these are the products we suggest for the project.”
3. Prelim Review and Feedback
Key point: There can be a fair amount of tension between the energy modeling and the financial modeling. How do you reconcile the two? Miller shared a good example from this project:
“In the Northern latitudes, your row spacing for PV rows is much further apart than it would be in the lower 48,” he says. “What we had to bake into these models was, I think 70 ft row spacing, which means our array is now much smaller … than what it would be in South Carolina for example. On the flip side, through energy modeling, we can look at different scenarios.”
Hear Miller explain those scenarios right here:
A software like Xendee that does both allows you to add different financial constraints, and energy goals, to produce optimized plans in one shot.
By the time the preliminary design is presented to the project owners, the engineering team should have several options and understand how any feedback or concerns from the project stakeholders will influence the models and budget.
“Once we all agree on what that path looks like, we pull together a report that is highly detailed, but it’s meant to also be concise so that it can be used for grant applications or interconnection applications,” Miller says.
The TCC has a general fund set aside just for grant writing and feasibility studies — the cost of a feasibility study being typically 1% to 3% of a project’s cost. The value in a thorough feasibility study is seen right away, by securing the initial grant, but also down the road, by mitigating risks and information design, construction, and O&M considerations before anyone grabs a toolbelt.
The webinar noted the importance of standardizing data collection, and the above process in keep that feasibility cost low. Xendee has been fine-tuning its tool for 20 years, to simplify what is essentially PhD level work. Here’s an overview of the platform:
4. Final Delivery
By this point, the engineering and analysis is well understood. The goal here is making that engineering and analysis easily understandable and readable for a variety of decision makers. It needs to be in-depth, but also clearly highlight why they would want to move forward.
“That could be a develop deciding let’s pursue this project or not, or that same report could be used for a grant application to receive more funding to actually build the project,” Miller says.
The eight communities had a similar electrical makeup. There will be variations at each site, but all based on this general concept. Let’s check out the end result in this handy animation:
Many microgrids are in some way connected to the broader grid and just have the ability to disconnect through a contactor automatic transfer switch. “In this instance, we’re really adding to an existing grid and making it more resilient,” Miller says.
Current setup: Centrally located generators with fairly traditional power lines operating at medium voltage to carry the power from the generators to the communities.
The plan: Add centralized switch gear next to the generators with on-site energy storage and remote PV arrays.
“Given the land constraints and geography, it made more sense to co-locate the batteries with the generators to have a central power hub with the switch gear acting as the brains of the operation,” Miller explains. “The PV arrays in many of these communities are a bit more isolated in plots of land that were open or have good solar exposure. So, we’ll be connecting the PV array to our switch gear through those medium voltage power lines, with everything tying together in that same generator house at that already existed.”
From here, the TCC is diligently working to keep the momentum going and move into the construction engineering phase. “If we effectively install these systems … we think that we’ll 100% be able to stabilize prices and we’ll be able to work toward actually lowering the costs,” Dellamary says.
To watch the full webinar, or key moments, click the links below.
- 00:00 – Introduction
- 02:06 – Speaker introductions
- 03:18 – TCC Project Overview
- 19:30 – Microgrid Feasibility Process
- 33:08 – Xendee Platform
- 41:40 – Project Results
- 45:29 – Impacts on the Community
- 57:16 – Speaker contact information
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