Installing Renewable Energy Technologies on Campus

Submitted by Walter Simpson on May 19, 2009 - 3:24pm
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Walter Simpson, AASHE Senior Fellow and retired 26 year University at Buffalo Energy Officer and director of UB Green, is working with AASHE and the American College & University Presidents Climate Commitment to develop climate action planning resources. You may read Walter's previous articles here.

Hello Campus Climateers!

It’s no secret that I think energy conservation and efficiency must be a – or rather “The” -- priority in college and university carbon emissions reduction efforts. But conservation and efficiency can’t take us all the way to the promised land of very deep cuts in greenhouse gas emissions or climate neutrality. Even after we have reduced our energy load to a bare minimum through conservation, we will still need to meet that load with something. As much as possible that “something” should be clean renewable energy – either from purchased green power or on-campus renewables.

Buying green power can make sense from a carbon emissions perspective if your purchase actually leverages new renewable energy development (and thus diminishes fossil fuel use). Strategies for doing this are explained in section 5.4.3 of the campus climate action planning wiki – though suffice it to say that not all green power purchases accomplish this; sadly, they may be more about “bragging rights” than actual environmental benefit. In comparison, all on-campus renewable energy projects do create a clear and undeniable environmental benefit.

Here are some options for on-site renewables:

  • Solar electric (photovoltaic arrays)
  • Solar hot water
  • Wind energy
  • Biomass
  • Geothermal
  • Fuel cells

All of these tend to be expensive. Simple paybacks tend to be longer and CO2 benefits tend to be less than energy conservation measures. But these projects are still worth doing – to start to make that transition to renewables and to raise awareness and educate the campus community, especially students – about the energy technologies of the future. Below are a few remarks about solar PV and hot water, wind energy, and biomass technologies followed by some wrap up suggestions on how to pay for and maximize the value of these technologies on campus.

Photovoltaics (PV)

  • PV will work anywhere the sun shines which is . . . everywhere. Per square foot of panel, there will be more daily and annual output from PV in Phoenix than Buffalo -- but PV works well in either location. If you want Phoenix-size output in Buffalo, you will need more panels – which of course will add cost.
  • PV is more cost-effective when electric rates are high and when local utilities or state government provide incentives or subsidies. If the latter are not available in your area, you may want to lobby your state public utility commission or your governor and state legislators.
  • Maximum annual output may be achieved by a flat array that gets more sun in the summer but less in the winter than an array with tilted panels. A flat array is cheaper to install and makes more efficient use of roof space, i.e. you can get more PV panels on a given roof area if the panels are mounted flat since tilted panels need spacing between them to avoid casting a shadow on each other.
  • Roof installations can work great but only pick a roof which can be seen readily. Your want your array to be highly visible wherever it goes.
  • There are a variety of financial models for installing PV on campus. Your school can buy and own the array itself or enter into a power purchase agreement with an installer who will own the array and sell its output to you.
  • If your school wants to take credit for the carbon-free power produced by the array, it will need to own or purchase the renewable energy credits or RECs produced by the array and not just the actual electricity. (This applies to all on-campus renewables.)
  • AASHE maintains a list of campus PV installations.

Solar Hot Water

  •  Solar hot water systems can be more cost-effective than PV yet are generally less common in part because installation and maintenance is more complicated and fewer incentives are available.
  • The best buildings for solar hot water systems are those with large hot water requirements, e.g. residence halls, food service, and athletic facilities. (Note: indoor swimming pools require year-round heating.)
  • Unlike PV, solar hot water systems must match daily hot water production with daily hot water demand. This can be a challenge if maximum campus hot water needs are in the winter months, a time when solar hot water system production may be at a minimum.
  • A power (or thermal) purchase agreement can also be used to finance an on-campus solar hot water system.

Wind Energy

  •   The huge size of the most efficient utility-scale turbines make them “out of scale” to the rest of a campus.
  • Smaller turbines can be installed on campus or large ones on the periphery of campus or on adjacent or remote campus property.
  • It’s financially advantageous to install wind energy capacity on the “campus side” of the campus electric meter to avoid “wheeling” or electricity transportation charges associated with delivering the juice to your campus.
  • There are lots of financing options available for wind including power purchase agreements and federal and state incentives, tax credits, etc. 
  • Building-mounted turbines may make a statement but they produce almost no electricity due to their small swept area. Also wind speed is likely to be reduced at lower heights and around buildings – further reducing output.
  • Before installing a wind turbine you will need to conduct a wind resource assessment – which may take a year. A small difference in wind speed can make a huge difference in turbine output because the power in the wind is a function of the cube of the wind speed.
  • AASHE maintains a list of campus wind installations.

Biomass

  • Biomass could be a good fit for a power plant replacement or for co-firing in an existing coal-fired campus heating plant.
  • When burned, biomass releases CO2 but it is theoretically carbon neutral because the CO2 released during burning is equal to the CO2 sequestered in the new biomass when it is grown for fuel. (Generally, there are fossil fuel inputs in this process – hence the “carbon neutral” characterization as theoretical.)
  • To use biomass, securing a guaranteed source of sustainably produced fuel is essential. “Sustainable production” of biomass fuel means, among other things, no cutting of forests.
  • A campus biomass cogeneration plant could produce near-carbon-free heat as well as electricity – a big plus for schools striving for climate neutrality.

Paying for Renewables on Campus
Just a quick idea: pay for these projects by incorporating them within an energy conservation performance contract. As mentioned in a previous post, we did this with a 73 KW PV array at the University at Buffalo. The large cost and long payback of the PV array got “lost” within a much larger performance contract. In other words, a $600,000 project was of little consequence to a $10 million large comprehensive project and ended up essentially being paid for by the conservation measures – so it was installed at no cost to the university. Can’t beat that!

Being Honest and Maximizing the Benefit of Renewables on Campus
It was no surprise that the electrical output of UB’s glorious 73 KW PV system, which covered much of the roof of UB’s Norton Hall classroom building, was equal to less than 10% of electricity used by Norton Hall! We could have denied that, along with the project’s long payback (18 years, after substantial incentives), but we did not. We used this information as a lesson. To make PV and other renewable energy resources better able to meet our electrical needs, we need to reduce our electrical needs! Yes, buildings like Norton hall should be much more efficient – and a PV array provides an opportunity to have that conversation. Other lessons were that PV efficiency needs to improve substantially and costs need to come down if this technology is ever going to rescue us from fossil fuels and climate change.

Renewables on campus make the most sense and produce the most benefit when they do the most teaching. Hence we need to be fact-based and in full disclosure mode about the actual energy production and costs of these systems. The installations also need to be highly visible (our roof top installation could be seen from surrounding buildings and from windows in UB’s science and engineering library) and be accompanied by interpretive energy displays and other educational media including kiosks and websites that show real-time performance and other pertinent information. If you do it right, the educational value will redeem the cost-effectiveness of these systems.

For more discussion on on-campus renewables, please see section 5.3 of the wiki.

Next time my topic will be new construction and green building design. As always, I hope these blogs are helpful.

‘till then climateers!

Walter Simpson
enconser@buffalo.edu

Walter Simpson, AASHE Senior Fellow and retired 26 year University at Buffalo Energy Officer and director of UB Green, is working with AASHE and the American College & University Presidents Climate Commitment to develop climate action planning resources.