Economical solar energy and energy from fusion have been identified as two of engineering's grand challenges. While work continues on these grand challenges, conservation of energy from non-renewable sources is vital. On a practical level, installing low thermal emissivity windows (low-e windows) on buildings can contribute to energy conservation. Installing low-e windows on a small office building is estimated to cost $10,500. The windows are expected to last 10 years and have no salvage value at that time. The energy savings from the windows are expected to be $2,150 in the 1st year. After the 1 st year, the savings are expected to increase by $225 each year due to escalating fossil fuel costs. MARR is 13% per year and annual worth is the preferred measure of economic worth. Part a Are the low-e windows an economically attractive investment? Click here to access the TVM Factor Table Calculator. The annual worth of installing the low-e windows is $ Carry all interim calculations to 5 decimal places and then round your final answer to a whole number. The tolerance is 1. The low-e window investment attractive