                        2000/02/07


  Stig Larsson                          My estate
  Bodvagen 19                           Sidsjobodarna
  853 57  Sundsvall
  Sweden
  Tel: 060-12 67 03         Email: sfp1785@post.netlink.se

 My energy bills since moving in.

 When I bought the estate 1971 in Sidsjobodarna and moved in, there was an
 oil heated furnace, which consumed 6000 litres annually.

 I have always been a natural environment supporter, and this destructive oil
 consuming house made me feel sick, despite very cheap oil. 6000 L was then
 $108 (SEK 1080). Today eqvivalent is about $1000.
 I added 50 mm insulation to the walls, thereby reducing heating need to
 3000 L annually.
 Fairly constant thru the years, despite my efforts to build both heat pump
 and solar collector.
 
 1990 I installed 8.5 m2 LARTEC prototype solar collectors. My own design.
 LARTEC has a selfdrained system filled with pure water.

 1992 I replaced the oil combustion equippment whith an electrical resistant
 heater.
 I was too busy to monitor heat consumption until 1997. By then, I had to
 shut down the solar system, due to water leakage.
 My son split the car garage, and decorated a one room flat, electrically
 heated thus increasing the heating bill up to 33,000 kWh/year.

 This was too much for me, so by march 1999, I corrected the solar collector
 error to get it back on line. The flaw turned out to be a broken pipe at the
 roof. Exposed to winter cold and somehow undrained, the water expanded when
 turned to ice and blow the pipe. This is a very rare event, but has happened
 a couple of times during the years. No damage are to be seen at the collector
 itself thow.

 1999 year consumption (ending y2k March one) is estimated 24,000 kWh, which
 is 9000 kWh less then the heat bill without solar system. Energy saving
 from solar system is then almost 1000 kWh/m2 x year, which is twice as much
 as normally spoken.
 My experience is that LARTEC often encounter this kind of savings, as we have
 a lot of installations reaching it.
 This is done by adjusting the house original heat control system for best
 performance.

 2000/03/02
 Well,the final reading showed  24300 kWh.
 A couple of cold weeks in Februari caused the meter to speed up.
 Still, the difference is 8700 kWh = $500 savings.
 I have checked with SMHI (Swedish metrological and hydrological institut)
 and 1999 was slightly chillier than 1998, so all savings is due to solar
 collector and better heat control.

 Have a good day

 Stig Larsson.
