Not having enough of these protective substances can cause stones. Changes in the Acidity of the Urine. Changes in the acid balance of the urine can affect stone formation. 1  Uric acid and cystine stones mainly form in acidic urine.
1 For an average sized 1,500 square foot roof, that works out to a total PVC roofing cost of $6,000 to $18,000. 2  While certain types of PVC roofing material can be installed over the existing roof, the old roof may need to be removed and disposed of at an additional cost of $1.00 to $2.00 per square foot. While certain types of PVC roofing material can be installed over the existing roof, the old roof may need to be removed and disposed of at an additional cost of $1.00 to $2.00 per square foot.
In addition, costs for fossil fuels may creep up due to raw material costs, shipping costs, and possibly carbon dioxide taxes. At an installed price of $1.25 per watt, the cost of PV solar is always cheaper than coal.At $2 per watt, it is cheaper after year 40.At $3.00 per watt, it is cheaper about year 80. roof top solar system has no moving parts, so it has a long expected lifetime exceeding 25 years (used in this example). However inverters (which convert the panel DC current into AC) have an expected lifetime of 10 to 15 years. In our example we add the cost of a replacement inverter to the system after 12 years.