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Sustainable Systems, Summer-Fall 2006


Solar Hot Water Project

Photo Gallery


Reference Tools

Future Lab Ideas

(place unused info like Pathfinder and Line-loss data)

Future Project Ideas

(suggestions for the next class)

ENPR 256 - Sustainable Systems, Energy

Reading and Exercises

  • Week of July 3rd
    • Estimate the dollar cost of hot water for Miller farm by month over the past 5 years. Write-up your model describing the data sources, assumptions, formulas, etc. using a wiki page here: Colin, Kate-Ehren-Dan. Note: See finished lab below.
    • If you are taking this course for upper-level credit (Ehren, Colin), talk to the instructor about your individual project.
  • Week of June 26th
    • Read the manual for the WattsUp meter. Set it up with a small load (light, toaster, rocket launcher, etc.) and try the different modes. Set the cost of electricity to the amount the College is paying (from the RP&L bills).
    • Document what you have learned so far about solar hot water and grid tied systems using the links below. Tank sizes and prices, conversations with agencies, etc.
    • A little basement cleaning and lighting would go a long way towards making the hot water heater monitoring gear installation on Saturday a lot easier.
  • Week of June 19th
    • Pages 76-122 in Reader's Digest Back to Basics
    • Read Colin's explanation of degree days (link below in Reference Material). Talk about it enough to make sure that you understand the details.
    • Work through (individually) the online energy audit at http://hes.lbl.gov using Miller Farm as the house. Make a note of your session number, you can return and re-calculate it.
    • Spend an hour or more browsing the Real Goods Solar Living Source Book. I want you to get a good sense of the range of gear available in this space and the complexity and costs associated with it.


  • Week of July 24th (Note that Ehren added this not Charlie)
    • Test the potential for using Charlie's spare solar hot water unit, and record the fun.
  • Week of July 11th
    • Figure-out and setup an open source based solution to monitoring the WattsUp? Pro via the serial interface. Document your work, with prose and pictures, here.
  • Week of TBD
    • Setup a WattNode TTL on a 110VAC line and interface it to a computer's serial port. Write a simple program to read the value off the serial port, convert it, and write it to a log. Compare the electrical usage of an idling computer for 12 hours using the WattNode/software combination and the WattsUp units. Document your work, with prose and pictures, here.
  • Week of June 26th
    • Setup a WattNode pulse on a 110VAC line with the LCD display. Compare the electrical usage of an idling computer for 12 hours using the WattNode and the WattsUp units. Connect them in serial so that each "run" includes both measurements. The WattsUp can be set to display in the same units as the WattNode's LCD. Document your work, with prose and pictures, here.

Documents in Progress


Reference Material

To Do

Near Term

  • Enter LP gas bills into the database (Colin)
  • Setup monitoring gear, plumb database interface
  • Continue research into cost of new tanks (Ehren)
  • Cleanup our weather data (Colin)
  • Build a local repository of Farmland's data or another nearby location, develop an interface (Colin)
  • Develop year-to-year comparison interface
  • Setup an on-going feed for the RP&L bills (Colin, is this possible?)
  • Track down the most recent wind survey data for this area
  • Track down the most recent solar incidence data for this area

Medium Term

  • Insulate bulkhead doors to basement
  • Insulate pipes in basement
  • Create annual energy calendar (Kate et al)

Long Term

  • Infrared scan of leaking heat for first cold day


  • Measured bulkhead door, tanks can fit (Kate)
  • Wrote up results of 12 hour WattNode/WattsUp? test run and posted on wiki with pictures. (Ehren, Kate, Dan, and Colin)
  • Calculated line loss for barn to house - N VDC (without inverter) and 110 VAC (with inverter) (Dan) Write-up?
  • Cleaned basement at Miller in preparation for installation of the WattNode monitoring gear (All)
  • Collected one year of LP gas bills (Kate)
  • When was hot water heater installed (Kate)
  • Conducted 12 hour WattNode/WattsUp? correlation test run (Ehren & Colin)
  • Contact IMPA about grid-tie system (Ehren)
  • Collected new-water-tank prices from TSC (Ehren)
  • Setup Wiki usernames (Charlie)
  • Rented solar pathfinder (Charlie)
  • Defrosted basement freezer (Ehren)
  • Cleaned and shut off 1 refrigerator (Ehren and Colin)
  • Performed perliminary energy audit (still have to get LP gas)
  • Created a table and populate the occupancy data for the Farm (Colin)