District Geothermal to reduce building heat output by qyz

Thanks again! Looks great. The DPW 5 year streets and sidewalks plan in our resources section outlines the next five years of priority streets for reconstruction. It would help us if you could look through that, see which streets may fit in here, and then look to see if there are clumps of houses, businesses that you feel would fit into such a program. Perhaps you could propose a pilot neighborhood? Thanks! - Jen

Thanks Jen, I did not find the 5 year plan on the resource page, but I did find it at the DPW website including this interactive map: http://www.cambridgema.gov/theworks/ourservices/engineering/weeklyconstructionhighlights/constructioninteractivemap.aspx As I 'm most familiar with East Cambridge I focussed in on the proposed repaving of Fulkerson and Thorndike Str., which, according to slide 16 on this presentation is scheduled for FY15: http://www.cambridgema.gov/~/media/Files/publicworksdepartment/Engineering/Five%20Year%20Plan%20Updated%20May%202014.ashx Fulkerson/Thorndike Str. has several advantages as a potential pilot project, including: 1. High density. Many residences and apartment buildings abut these streets, making it a potentially optimal location for attracting district geothermal customers. 2. Cambridge Str. business district. There are many businesses located on nearby Cambridge street, creating the potential for some of those businesses to choose to participate in district geothermal. This would require connecting to their location, but that should not be terribly difficult given the close proximity. 3. Elevation. Thorndike street is a relatively elevated area, potentially creating some protection from groundwater and other issues. 4. Community centers. Several community centers are nearby, including the Kennedy Longfellow school (abuts Fulkerson Str.), the city's School Administration building (on Thorndike Str.), the O'Connell public library branch (also on Thorndike Str.), creating opportunities for the city itself to take advantage of the Geothermal system and obtain energy cost savings in its operations.

Congratulations on making it to the Semi-Finals for the Urban Heat Island Effect contest. Please take into consideration the comments left by the judges and do please incorporate that feedback into your final proposal. We would also like to see a bit more detail on the impact locally. How will this be feasible in Cambridge and what are the barriers needed to overcome here? We look forward to seeing your ideas finalized in the next iteration!

Hello Quinton, Geothermal and Aquathermal are both available through the water system...if...the lake is aggressively cooled. If cold water is delivered through the water pipes, the property owner can use the thermal inertia in a number of useful ways. If we can build up thermal inertia during the winter or through bio-energy inputs during the summer, the lake can become available as a city wide sink (one aspect of the CHIP proposal). The river has great potential yet the regulatory burden when working with waterways is substantial. However, I would like to see the City use that important asset as, once it is in play, we may be able to expand the mission to include water filtration to support littoral health. You mentioned using the harbor as a heat sink (which is supportable). However, you may also want to take a look at the airport. The large open areas that the airport offers can be useful both as a heat sink and as an underground bio-fuel production tank farm. Obviously, the airport will want access to the fuel and thus a straight barter, land for bio-fuel, may be realistic. Best regards, Michael

Response to judge 2: I've quantified the UHI contribution of waste heat from air condition above, thanks for asking :-) I don't believe this would be a major hassle for city residents because it would be done only on streets that are to be re-paved anyway. It might add a little bit of time to the road re-construction, but compared to sewer separation this should be a breeze :-)

Quinton, On the AC waste heat issue, please read below; http://journals.ametsoc.org/doi/pdf/10.1175/2010JAMC2538.1 A Study of the Urban Boundary Layer Using Different Urban Parameterizations and High-Resolution Urban Canopy Parameters with WRF FRANCISCO SALAMANCA AND ALBERTO MARTILLI Research Center for Energy, Environment and Technology (CIEMAT), Madrid, Spain Abstract: "During the night, this anthropogenic heat was responsible for an increase in the air temperature of up to 2C in the densest urban areas,". page 1125 "In agreement with other studies (Ohashi et al. 2007), the waste heat increased the air temperature by 0.58–2C depending on the location inside the city and the day considered (meteorological conditions)". If we also take a look at the energy cost of this phenomena, factored out over the population, the cost of alternative cooling means and methods starts to come into focus as a possible utility level option. And, providing state-of-the-art alternative cooling means for buildings, at both the internal and external spatial dimensions, may be worth consideration by the City government. The use of thermal inertia, either through geo/aquathermal and or cold water misting (both options also found in the CHIP proposal), may possibly be the most direct path to mitigating the worst of the peak UHI effects. However, we can go even further. We also have a possible additional tool in mitigating this waste heat issue. In that, if a simple Stirling engine is mated to existing medium to large AC units, using the waste heat and cooled water from geo/aquathermal/cold water misting etc., the Stirling engine can energize a Emissive Energy Harvester (EEH) and transmit a majority of the waste energy into space. Simply "beam it up, Scotty"!! http://sjbyrnes.com/pub_PNAS_2014.pdf Or, the Sterling's energy output can be used to energize secondary space coolers or the converted energy can simply be stored in onsite Organic Flow Battery (OFB) systems for later use. http://www.nature.com/nature/journal/v505/n7482/full/nature12909.html I hope the above shows that we currently have a wide range of truly advanced options to use and that they offer us a high degree of flexibility in mitigating the UHI. Michael

Hi Quinton: Thank you for submitting this well-thought out proposal. While we think it has merit, specifically surrounding the equity piece of your idea, we feel that another of your proposals is more innovative, realistic and measurable. Thank you again and good luck in the finals! Sincerely, Jen