Please answer this engineering economy problem for me fully

Five years ago, a company in New Jersey installed a diesel-electric unit costing $45,000 at a remote site because no dependable electric power was available from a public utility. The company has computed depreciation by the straight-line method with a life of 10 years and a zero value. Annual operation and maintenance expenses are $18,000, and property taxes and insurance cost another $3 000 per year. Dependable electric service is now available at an estimated annual cost of $30,000. The company in New Jersey wishes to know whether it would be more no economical to dispose of the diesel-electric unit now, when it be sold for $30,000, or to wait five years when the unit would have to be replaced anyway (with no MV). The company has an effective income tax rate of 40%and tries to limit its capital expenditures to opportunities that will earn at least 15% per year after income taxes. What would you recommend? The AW value for the defender is $ (Round to the nearest dollar.) Five years ago, a company in New Jersey installed a diesel-electric unit costing $45,000 at a remote site because no dependable electric power was available from a public utility. The company has computed depreciation by the straight-line method with a life of 10 years and a zero value. Annual operation and maintenance expenses are $18,000, and property taxes and insurance cost another $3 000 per year. Dependable electric service is now available at an estimated annual cost of $30,000. The company in New Jersey wishes to know whether it would be more no economical to dispose of the diesel-electric unit now, when it be sold for $30,000, or to wait five years when the unit would have to be replaced anyway (with no MV). The company has an effective income tax rate of 40%and tries to limit its capital expenditures to opportunities that will earn at least 15% per year after income taxes. What would you recommend? The AW value for the defender is $ (Round to the nearest dollar.)