HomeMy WebLinkAboutGalena Biomass Tonnage Requirement Calculations 6 9 09 1
Biomass Tonnage Requirement Calculations
Revised 6/9/2009
BTU’s per pound of wood Average is 6500btu’s/lbs
Taken from Firewood rating and info sheet.
Verification of this number came from Andrea Gibson at AES who
estimated 6675 btu’s/lbs
Hurst Boiler requirement 55,027,300btu/hr at max fire rate
At 800kw average or 80% fire rate = 44,021,840btu/hr divided by
6500btu’s/lbs = 6,772 lbs/hour
AES estimated a demand at 100% load of 3,595 lbs/hour
Annual consumption is then 6,772 lbs/hr x 8760hr/yr = 59,322,720#
or converted to ton’s that equals 30,000 tons ( for the Hurst boiler)
Or per AES it is 3,595 lbs/hr x 8760hr/yr = 31,492,200 lbs so
converted to ton’s that equals a little less than 16,000 tons
So for estimating purposes we will use an average number of
23,000 tons per year as the requirement for wood chips.
So thinking about production in the woods. The chipper is capable
of 90 tons per hour so it won’t be the limiting factor. I think the
limiting factor is the haul rate. If a tractor is carrying 15 tons/trip and
makes 1 roundtrip per hour your production with 2 tractors would
be 30 tons per hour. Don’t yet know the physical size of the chip
bins on tracks to estimate their carrying capacity. If we have to add a
3rd tractor to increase production it will make sense to do that. Only
some time out actually felling & chipping is going to tell us what is a
realistic chipping & hauling rate.
2
So I am going to predict a production rate of 30 tons per hour.
Therefore to produce 23,000 tons @ 30tons /hr would take
766hours or divided by 10hr/shift = 76.6 shifts, so our biomass cost
would be 76.6 shifts x $7580/shift = $580,628.00
+ Seasonal cost of $200,000.00
For a total fuel cost of $ 780,628.00/ year
Add the annual capitol costs $ 864,000.00
O & M $ 899,040.00
Grand total annual cost $2,543,682.00
Divided by 12 months = $ 212,000.00 monthly
On the power production side each penny increase in electric rates
brings an additional $5,760/ month in revenues.
On the Steam heating side each $1 dollar/Mbtu would bring in an
additional $2,500/month in revenues
With the current steam plant at 80% efficiency burni ng oil. Each
gallon of oil contains 123,000btu’s x 80% efficiency =
98,400btu/gallon of oil so the equivalent rate would be
1,000,000btu divided by 98,400 btu/gallon = 10.16 gallons/Mbtu
The numbers below show a comparison to determine viability.
At a $20/Mbtu rate div by 10.16 gal/Mbtu = $1.97/gallon equivalent