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Calculate the cost of heating and cooling a greehouse.

The question is best answered by using an example, but first some formulas: Watts=amps*volts 1 KWH = 3,413 BTU 1500W electric heater produces 5120BTU Propane is 91,600BTU/gallon Q=deltaT*A/R Q=BTU heat requirement per hour delta T is the difference between outside temp and desired inside temp A= the surface are of the greenhouse is square feet, not including the floor; ie, the roof, side walls, and end walls R= the R value of the glazing

Two important points about this last formula...some heating calculators use "heat loss value" (HLV) instead of R-value. Don't get confused, the HLV is just 1/R. The formula using heat loss value is then Q=deltaT*A*HLV. The other important point is that you use a different temperature when calculating your average energy costs over a month than you do when you you calculate what size heater you need. Heater calculations are used to determine how much heat you will need on the coldest night of the year. For this, you use your coldest winter temps, for example the colder end of your zone. For calculating heating costs you need the average temperature for the month.

Here are some typical R-values for common glazings or coverings: 4 mil polyethylene 0.83; 4 mm (5/32") twinwall polycarbonate 1.43; 6 mil polyethylene 0.87; 6 mm (1/4") twinwall polycarbonate 1.54; 6 mil poly double layer (inflated) 1.43; 11 mil woven polyethylene 0.95; 3 mm (1/8") glass (single layer) 0.88; 16 mm (5/8") triplewall polycarbonate 2.5; Polycarbonate/fiberglass (single layer) 0.83

OK, let's say we are contemplating an ACF 10 x 12 Cottage Greenhouse. We first need to calculate the surface area of the greenhouse. Using the diminsions found on the website and some simple geometry, we calculate the surface area of each sidewall to be 55 sq ft, each roof side to be 64.6 sq ft, and each end wall to be 75 sq ft. Therefore the total area (A) is sq ft is (55*2)+(64.6*2)+(75*2)=389.2 sq f

The best metric is energy per unit weight, about 120-150 w-hr/kg for current commercial Li-ion rechargeable batteries. We expect that 500-700 whr/kg can be accomplished in the near term, rising to 1200-1500 whr/kg in the longer term (for the engine and its fuel supply).

TTPS is therefore a facility of strategic importance for meeting Ghana 's energy needs.

The current installed capacity of the Takoradi Power Plant is 550MW and is to be upgraded to 660MW by the CMS/VRA joint Venture. The wholly –owned VRA portion of 330MW combined cycle Plant with a 2x2x1 configuration meaning two (2) 110MW GE Frame 9E combustion gas turbines, with two (2) HRSGs feeding one (1) 110MW Steam Turbine Generator. The voltage output of the Generators which is 13.8kV is stepped up by Power Transformers to the national grid system voltage of 161kV.

With the objective of being an electrical supplier of choice for customers in Ghana and West Africa , the Plant operates on two modes, namely Simple Cycle and Combined Cycle . The primary fuel used for power generation is Light Crude Oil (LCO) which is normally received from ocean tankers via a Single Point Mooring (SPM), connected to the plant by approximately 4.5km undersea pipeline and stored in four (4) 29,500m 3 capacity storage tanks. The secondary fuel on site - Distillate Fuel Oil (DFO) is normally used for start-up and shutdown as it is less volatile. On the average, a Gas Turbine at base load (110MW) can generate 2.5GW of electricity using about 890m 3 of LCO a day.

The Plant has dual firing capacity and is being converted to run on natural gas. In the Simple Cycle mode, the exhausts from the Gas Turbines are directly discharged into the
atmosphere at temperature of about 560 degrees C through exhaust stacks. In the Combined Cycle mode, the exhaust gases from the Gas Turbine are used to generate super heated steam at a rate of 160t/hr at 520ºc and a pressure of 54bar through the Heat Recovery Steam Generator (HRSG) to turn a Steam Turbine.

The solar module manufacturing facility opened in Wrexham in 2004. According to reports, the cash injection will total approximately £9.3m.
Soaring demand for solar energy systems in ... has driven Sharp to double production in Wrexham.
The company said in a statement, "Production capacity will be doubled and the existing 110MW capacity will be expanded to 220MW, and this expansion will make the facility one of the largest PV solar module plants in the world."

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