We are all hindered by unintended consequences, Sweden one might argue a global leader for harvesting leftover heat was hamstrung by the law which prevented other suppliers accessing the district heating grid, but that changed when a law was passed last year that allows outside suppliers to deliver heat through the district heating grid. Now the town of Kiruna in northern Sweden can use waste heat from their local industry to cheaply heat homes, a neat solution when the mercury hits -30 Deg C in winter. Details are scarce in the Guardian article  however using waste heat whether from industry or power generation is cost-effective when the distance (where increasing distance equates causing increasing heat loss) between the source and end-user is not great.
Less commonly known is that waste heat can be used in the tropics to drive air conditioning, necessary in large parts of Asia. Low grade heat energy is often dumped into rivers or the sea, instead it can be used to change the concentration of liquid salt, e.g. lithium bromide, creating cold water for comfort cooling.
Handling food waste is a global problem, but is all food waste equal? There is waste from dining generated in homes, restaurants, and Dai Pai Dong’s, and there is food waste from markets, wet markets, and supermarkets, the latter being merely past its sell by date. HKSAR Government intends to create four food waste to energy plants, but no mention of their location and tragically RTHK’s report confirms our fears, about 3,000 tonnes are dumped into landfill every day! That is 1,095,000 tonnes per year.
However, collection, handling, shipping it across the territory, and bulk storage in central facilities is the worst possible solution in my view. To tackle local problems we need local education and local solutions, shipping it “way” will only perpetuate the most common reaction NIBMY.
Eco-District or community scale solutions demonstrate locally there is no distant landfill to handle the waste, you use it, you see it, you handle the waste. Therefore encouraging participation in the solutions, today’s over emphasis towards Green/Smart cities overlooks an important aspect, the human scale. The biggest challenge for eco-districts will be success, where the WTE (waste to energy) plant and equipment is designed for the worst case scenario, and the neighbours begin to understand that their waste creates a local waste problem, over time the total volume of waste will shrink, leaving oversized equipment in its wake. We need District, not City scale solutions.
We know there are insufficient resources to go around, right? Perhaps not. However, there are options, the idea of one planet living (http://www.oneplanetliving.com) gives guidance, like David Letterman’s feature, it provides a convenient top ten list, but how can we migrate from the status quo to a more sustainable future?
Green Building or clean technologies? What is the solution? Well in reality it is not that easy, I have seen Variable Frequency Drives (VFD) intended to provide fan speed control and save energy, locked at one speed, I have seen the building’s central chiller plant operated when one room demands cooling, I have seen room temperature sensors located above lighting fittings (lights are heaters) therefore the air conditioning system continuously calls for more cooling. etc.
So if I have learned one thing, it’s not the latest new idea or the wizbang technology itself that matters, what really matters is how we use the equipment and operate the facilities.
But before we all become operator angels, we will need to optimise and improve design, and not just buildings, but their context, we need more design not less, and we have to be prepared to pay for it. The challenges we face require scaled solutions, beyond a single building, and communities provide sufficient scale to enable working solutions (see also Every Community a Powerhouse).
And these solutions should be local. In my diagram above, waste can be managed AND reused. For example, water a separate stack would collect greywater for reuse primarily within the community, for example irrigation or process water for local industry.
Its more important than ever before that Eco-districts cover all aspects of our daily life including work! In the USA vast cities developed where work and home are very separate, with little public transportation, the urban sprawl created the un-walkable distance, increasing the demand for a private car, and in reality more than one car.
Creating distal residential areas in remote isolation is a recipe for disaster, we need closer communities, communities where certain resources can be shared or call them eco-districts, which are places we can work, play, and live.
We must optimise the use of resources, rainwater can be captured from several buildings are used communally for industrial use, irrigation, or your local energy generation. We have become accustomed to throwing things away, out of sight – out of mind, but there is no away, a far better solution is to handle all waste locally, and yes we should encourage more recycling, but we must be practical, and the local reminder (that there is no away) should be visible in your backyard, and it should be used locally whether for power generation, compost, or biogas (fuel for cooking) when possible locally.
We invest in expensive and energy-hungry air conditioning systems for offices that are typically used 9-7, then we repeat the investment and resource use, providing air conditioning for homes, with a little planning forethought, and load profile analysis, one AC system could serve both the office (during the day) and our homes (outside office hours), this natural synergy would save considerable cost and resource use.
The technology exists, but that is the easy part, we need solutions at scale, we need Government, stakeholders, communities to embrace change, and start managing and operating the entire planet.