Biomass District Energy and Cogen Worksheet

Developing a district heating and cogeneration facility is a long process.

Typically, it involves four steps:

Concept: identify champion, do a preliminary assessment, develop working group
Feasibility: gather information, do a detailed study, set ownership structure, negotiate with financiers, suppliers and purchasors
Construction: obtain approvals, design, construction, commissioning
Operation: including maintenance

This worksheet will help you to take the first step and explore the concept of district energy. The success of a biomass district energy system depends on many factors.

The worksheet will help you to take a preliminary look at the various factors as they apply to your situation and determine if you should consider district energy as a serious option.

A. Energy Loads

Are your electrical and thermal energy loads suitable for district energy? 
Cogeneration systems are at their most efficient when electrical power and 
heat demands are uniform and simultaneous over a long period.  The 
characteristics and size of the energy load are equally important.  
Is the thermal energy required for space heating or process heat?  
What are the temperature and pressure requirements?  Is there a reasonably 
continuous demand for electricity and heat?  

If the host enterprise does not have sufficient energy load, identify other 
major energy users in the community to supplement the demand and provide a 
better energy profile.


Average size of energy load:   electrical..................kWh per month
    
    thermal .......................    

Are energy loads uniform?  What is the variation on a monthly, weekly and daily
basis?

...........................................................................

Are thermal and electrical demands simulataneous? ...................

Thermal load characteristics:    end use:  
         process heat.........................   
         
         space heat...........................
    
         temperature requirements ...................................
    
         pressure requirements ......................................


B. Energy Costs

As a rule of thumb, these district energy systems are feasible where combined 
heat and power costs exceed $100,000 per year.  If your energy requirements are 
not large enough to support a system alone, you could consider combining with 
another major energy user in the community.

 Monthly heating costs ..................

 Monthly cooling costs ....................

 Monthly electricity costs .................

 Total monthly energy costs .................

There may also be wood waste disposal costs which would be avoided through 
using the wood waste in the district energy system.  These should also be 
factored into the equation.

Cogeneration is a favourable alternative where biomass fuel is relatively 
inexpensive compared to other fuel sources and high electrical purchase rate. 
What are the purchased costs of energy in the region:

  fuel ...........................................

   electricity ..................................  
   
   biomass fuel ..............................


C. Biomass Fuel 

A reliable source of biomass fuel is a critical factor.  Use this section to 
identify the source and volume of available fuel, including waste wood from 
your own operations, if applicable.

What is the source of biomass fuel, i.e., sawdust, chips, hog fuel etc.? 

..............................

What are the characteristics of the fuel? ..............................

What volumes are available on a regular basis? ..........................

Are there likely to be limitations to the availability of fuel? .........

    ....................................

Is there a cost associated with the biomass fuel? ........................

Are there any regulatory restrictions on burning of biomass fuel in the region?

     ....................................


E. Capital Costs

As with any retrofit project, the extent of modifications required will affect 
the financial viability of the project.  Also, projects can become more cost 
effective where retrofit work can be piggy-backed onto other work which must 
be done.

Are there major modifications which would have to be made to buildings, 
services or processes in order to accommodate a district energy system? 

      ...................................... 

Is there already a need for capital investment to replace or upgrade an 
existing facility?

       .........................................  

Is a new heating plant required? ....................................

Is there a district heating network already in place?  .................

If not, what are the distances involved to connect major users on the system?

       ........................

Return to biomass information package.

For queries or suggestions, please forward to:

IPPSO, PO Box 1084 Station F, Toronto, Ontario, M4Y 2T7 Canada.
Street address: 163-C Eastbourne Ave., Toronto, Ontario M5P 2G5
(416) 322-6549 fax 416-481-5785 Internet e-mail: ippso@web.apc.org

Last update: 8 July 1995 URL:http://spinne.web.net/sustenergy/biomass_worksheet.html ÿ