Friday, November 5, 2010

Free Heat?! It's Just Under Your Feet!

A match made in sustainability heaven?

The mayor of Philadelphia has declared that his city will be the nation's "greenest city." An extraordinary number of competitors vie for that distinction, with cities such as Portland, Oregon, having many more years than Philadelphia out of the starting gate.

But I experienced a rush of confidence that the mayor's claim of sustainability is not an empty boast. That confidence is tied to an eureka experience in seeing the "synergy," specifically an "effluential synergy," at play with two locally-owned companies.

Michael Sebright, a Chestnut Hill resident in Philadelphia, "creative officer" of Energy Reconsidered, has the right to use IsoMax Zero-Energy Building Systems in the United States. This technology sandwiches a fluid circulation system within interior building panels on exterior walls, in which the fluid is warmed or cooled by a heat pump from water sourced, in the standard model, in geothermal tanks and with energy from solar thermal panels. Got that? The wide experience in Europe is that solar thermal energy is sufficient to provide all the space heat needed, even in northern Europe.

The challenge to solar thermal in a city is the relatively small roof area typical of Philly row homes. IsoMax also requires installation of a geothermal tanks, which is complicated in a small rear yard or in a narrow basement.

So that kind of hurdle is where enters the second bright light on the horizon of Philadelphia sustainability ventures: NovaThermal Energy. This company has technology to extract heat from sewage flowing in the city's sewage collection system. Whereas a typical family uses 10,000 cubic feet of natural gas annually to make hot water, and it all quickly washes down the drain and into the sewer system, a vast quantity of inaccessible BTUs of wasted thermal heat is flowing in the 3,000 miles of sewers buried under Philadelphia city streets. But NovaThermal has a technology, now deployed in China, to "borrow" the sewage just long enough to pull out those BTUs. In doing so, NovaThermal uses, as does Energy Reconsidered, heat pumps to amplify the temperature of the fluid to put the energy into a form usable for heating building spaces.

NovaThermal's technology, championed by Chestnut Hill resident Elinor Haider, is still brand new to the city and to the U.S. In fact, just before Halloween a major first step to development of a "reference facility" in the States was taken. The company's web site announced a funding grant from the Greenworks Pilot Energy Technology Program for the installation of a system for heating a 20,000 square foot building at a Water Department facility using funds.

So here is my eureka moment!

We have here a match made in sustainability heaven. Let's combine the capability of the NovaThermal technology to extract heat from the sewer with the capability of Energy Reconsider's IsoMax to efficiently use sewer heat for building space heat. In this way, the BTUs in hot water drained from up-sewer homes gets a second chance to be useful in homes down-sewer.

Next step?

The saying goes: "many a slip between the cup and the lip." Nevertheless I recommend a conversation around a table at the Chestnut Hill Coffee Company. Can you imagine a more powerful result than having a carbon footprint for home heating that is actually in the opposite direction? Now that is sustainable!

And, for me, this is a compelling "effluential synergy."

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