Developing Beyond Sustainability

Linden Hills Power & Light (LHP&L), is a neighborhood-based organization aiming to shrink our local carbon footprint through education, community engagement and action.  We promote sustainable energy, waste reduction and energy conservation. We are currently focused on two priorities: 1. Making the curbside organics collection pilot a great success, with the aim that it continues in Linden Hills and is expanded to other neighborhoods in the city. 2. Pursuing the development of an urban Anaerobic Digester (AD) to process organic waste and produce renewable energy.

 

LHP&L's mission is to reduce our local carbon footprint through education and community action, by promoting sustainable energy, waste reduction and energy conservation. We have been working with the city on a pilot collection of biodegradable (compostable) material. Taking biodegradable waste out of the trash has many environmental benefits. All households except multi-unit dwellings with more than four units are eligible to participate (apartment buildings and businesses can opt to modify contracts with haulers if they want to join). We have completed a feasibility study on the viability of a neighborhood anaerobic digester, to see if we could use the neighborhood's waste to create energy that would benefit the community.

 

We're also encouraging residents to participate in the MN Energy Challenge -an online tool that shows how small steps can have a big impact in reducing carbon emissions and global warming.

 

An association of 80 homes could definitely have a thermophillic anaerobic digester to produce methane to power their homes.  The smallest commercial size for this technology is approximately 5-10 tons per day and this size will produce enough pipeline quality gas to provide all of the heating needs for 30-50 homes.  The economics are a question that Linden Hills Power & Light is wrestling with.  We have just completed a feasibility study that compares the economics of a 5 ton per day facility with larger sizes that might provide close to all of the heating needs of our 4,000 home community.

 

Anaerobic digestion can be an integral part of the solution to two of the most pressing environmental concerns in urban centers: waste management and renewable energy.

 

In the anaerobic digestion process, specialized bacteria decompose organic matter (leaves, grass, tree clippings, food waste, pet waste, paper that's been in contact with food; items high in moisture) in an oxygen-depleted environment to produce biogas and a stable solid. Each of these products can be used for beneficial purposes to close the loop in organic waste management. Anaerobic digestion has been successful in reducing the volume of waste going to landfill, decreasing emissions of greenhouse gases and creating organic fertilizer.

 

-  Making the curbside organics collection pilot a great success, with the aim that it continues in Linden Hills and is expanded to other neighborhoods in the city.

 

- Pursuing the development of an urban Anaerobic Digester (AD) to process organic waste and produce renewable energy.

 

- Once you sign up to participate in the pilot, the city will deliver a 65 gallon green "organics" cart to your home. It looks very similar to your normal black wheeled bin that you bring out to the curb before your garbage collector arrives. From then on, you will wheel both bins out to the curb on your regular collection day and the city will take your compostable garbage (green cart), and your non-compostable garbage (black cart).

 

- Currently Minneapolis residents recycle around 35% of their garbage.  Collecting organics could increase that to about 75%, leading to a massive reduction in landfill space.

 

- At present, 75% of Minnesota’s electricity comes from burning coal. If the Linden Hills digester is successful, the technology could be replicated in neighborhoods across the city, state and beyond.

 

- Operating costs without including revenues from energy and bi-products will cost around $90 per ton.

 

- With current natural gas prices included into the revenues, the operating cost may come down to $45-$65 per ton.

 

- Revenues for carbon credits, compost, and CO2 might bring the operating cost below the estimates in #2.

 

- The cost of garbage collection exceeds $100 per ton.  If any cost savings and/or tipping fees for Source Separated Organics such as yard waste and food wastes can be received by the operating entity and these revenues cover operating costs, then you may have a viable project.

 

 

 

- The organics cart from the city can be kept outdoors, wherever you keep your regular black trash cart. You may want to consider switching to a smaller black cart after a few weeks of the pilot if you find yourself having very little non-recyclable waste. (You will save $2 per month). As far as in the kitchen, there are a number of options.

 

- Convert your usual kitchen trash can to biodegradable only (using a compostable bag, or paper bag not regular trash bags. If you use paper bags, wrap the wet organics in three sheets of newspaper before tossing in the paper bag so it doesn't fall apart when you lift it!), and place all the plastic/non recyclable metal, etc elsewhere in a smaller receptacle;

- Consider a pull out "trash drawer" for trash with multiple compartments so you can have the organics in one compartment, recyclable paper in another, non-recyclables in the third to fit your needs. Make sure the organics compartment has a biodegradable liner or paper bag liner as all material that goes in the green cart needs to be bagged in some way (this excludes paper products such as pizza boxes, and other food soiled-cardboard which can be placed in the cart without sticking to the sides.

 

- If you don't have a lot of food waste you might consider a counter top compost container, however these won't fit fridge and freezer packaging and will need to be emptied more frequently.

 

- In all cases, just be sure to wrap your food scraps in newspaper or place in a compostable bag, so they don't stick or freeze to the sides of the outdoor cart. See some options below courtesy of the website www.thisoldhouse.com. This type of sectioned drawer can be found at places like the Container Store; Storganize, Home Depot, etc.

Received a $45,000 grant from the Minnesota Department of Commerce. The project has received $30,000 from the Minnesota Pollution Control Agency and matching funds of $67,000 from national energy experts.

Trash recepticals, Anaerobic digesters (industrial systems that recycle organic matter and use the resulting biogas — mostly methane — as an alternative energy source).