Author: Mark Owkes

Cohousing’s commitment to energy efficiency and sustainability

That’s right. Bozeman Cohousing has officially declared net zero carbon intentions. We’ve set aside $400,000 of our budget to equip our whole community with solar panels on homes and/or garages. The exact placement will be determined by comparing sun load at each location. This proposal was approved unanimously.

What does Net Zero mean? 

“Net zero” refers to the balance between carbon emissions produced and carbon emissions taken out of the atmosphere. In order to halt climate change The Paris Agreement sets forth the goal of 1.5 degrees Celsius warming target by mid-century. And to get there the IPCC reports that CO2 emissions must fall to zero. This doesn’t mean that CO2 cannot be emitted ever again, but we must balance our output and our input, and ideally have negative emissions. 

Why did we do it?

Bozeman Cohousing recognizes the reality of climate change and the necessity of humans working together to combat this crisis. Since the industrial revolution, the influence of human activities – primarily burning coal, oil, and gas – have caused excess greenhouse gases to accumulate in the atmosphere, thus amplifying our atmosphere’s natural ‘greenhouse effect’ which warms the earth, the oceans, and increases climate instability (floods, droughts, fires, hurricanes). We’re changing the chemical makeup of our atmosphere and our oceans. This is a global crisis.

Our vision states: “Our community is designed and constructed with an emphasis on sustainability, which our lifestyles reflect.”  We believe that to set our community up for success to achieve the goal of net zero carbon required an adjustment to our budget and designs to include solar arrays from the start.

Our community is designed and constructed with an emphasis on sustainability, which our lifestyles reflect.

–from Bozeman Cohousing Visions Statement

What was our thought process?

Proposal: Include in the budget the cost of sufficient solar photovoltaic arrays (solar panels) to reach the project’s Net Zero Carbon goal.  

Questions raised by the community

1. How will this impact the cost of homes? 

Studio Co+hab estimated the size of the solar array needed to be ~200kW or about $400,000 total based on Cadius’ Solar Division’s cost of solar installations. This analysis was presented at the Private House Workshop. The cost of the solar installation would be distributed like other construction costs on a per-square-foot basis averaging to about $8,500 to $16,000 per household. (Energy use scales relatively linearly with home size.) There is a 30% federal tax credit available for renewable energy purchases, which is already factored into the price.

2. How would this impact HOA dues? 

It would lower the cost of occupancy by ~$750 per household per year. That would likely be a reduction in energy bills, rather than a change in HOA dues, however that structure has not been determined at this time. Based on installation costs and avoided energy costs the estimated payback is approximately 13 years. 

3. How would the systems be owned? 

A: Unknown at this time. There may be an advantage to commercial (HOA) ownership for some or all of the solar. It may also make sense to have the arrays tied to each home at their electrical meters.  In Cadius’ South Rows project, each array is owned by each unit. This is a question that would need to be investigated as a solar array design moves forward.

4. What are the benefits of doing solar now vs later?

Solar Now

+ Climate change is an immediate issue now, not later
+ We can use being net zero for marketing
+ We get to live our values at move-in
+ Some money may be saved through economies of scale
+ Less hassle, administrative time, and cost doing it during construction
+ The project will have a single array type, so maintenance is simpler/consistent
+ Roof life is extended under solar panels, often more leak-proof fasteners and roof penetrations can be used during initial construction
+ NW Energy is trying to make the net metering agreement far worse; now would likely grandfather the project’s solar metering structure
+ Energy prices may/will likely go up in the future making an investment in solar now increase in value over time
+ Investments in solar can historically be recouped at the time of home sale
+ It will not look hodgepodge
– Home prices increase by an average of $10k
– Debt buyers have to qualify for a larger loan and pay interest on it

Solar Later

+ Lower initial home prices
+ A homeowner could have more flexibility in the size of array
+ Solar technology is slowly and continuously improving while costs are slowly decreasing over time
+ Perhaps better state or federal solar rebates/tax credits will exist. The opposite is also a possibility. (The current administration has worked to try to end the federal tax credit, though ultimately the authority rests with Congress, which does not appear likely to act on this issue).
+ Solar rental companies may exist in Montana in the future, eliminating the need for large cash outlay
– The opposite of most positives in the “now” category

The members discussed the impact of changing tax credit over the next several years and brought up whether purchase would be community-wide vs. individual units. Ownership is still to be determined. 

Decision:  Unanimously approved.