Thermoelectric-generator is combined with thermal-photovoltaic in two proposed cycles. The first cycle is an once-through water flow from the collector to the storage tank, and the second one with circulating water from the storage tank to the collector. The thermoelectric-generator extends electricity generation using the stored hot water in the storage tank during the night and also can reduce the size of battery bank and solar panels in off-grid systems. Both cycles are modeled and the thermal-photovoltaic, and thermoelectric-generator models are validated, and good agreement is achieved. The heat source and heat sink fins are designed in details. The thermoelectric-generator efficiency is low due to low temperature of hot water. According to the results, the first cycle is more efficient from the energy, exergy, environmentally, and economic point of views. In addition, both cycles have positive net present value (NPV) for interest rates of less than 10% but the first cycle is more safe for investment because its NPV will be zero at interest rate of 15%. The sensitivity analysis showed that the economics of the cycles is more sensitive to the interest rate. In addition, the first cycle with a photovoltaic thermal (PVT) area of 1.623 m2 reduces carbon dioxide generation of about 365.1 kg per year.
