IntroductionDaylight is the preferred source in buildings due to its beneficial effect on human well-being and performance. Its potential to save energy and therefore protect the environment has stimulated interest as a substitute for electric lighting. The recent development of “daylight guidance technology” allows daylight to be redirected to areas of buildings that cannot be illuminated by conventional glazing. The two main types of guidance are the commercially successful tubular daylight guidance systems (TDGS) and the newer hybrid daylight/electric systems (HLS). This study of the costs and benefits of hybrid systems makes the case for using this form of daylight provider as an alternative to TGDS in combination with a conventional electric lighting system (ELS). Evaluation Methodology The methodology used to evaluate the costs and benefits of the system is the full life cycle. Cost calculation (WLCC). This provides more realistic comparison data than the simple retrieval method that is commonly used for evaluating lighting systems. Full Life Cycle Cost (WLCC) WLCC takes into account the costs of operating and operating buildings (or their components) over their lifetime, as opposed to a specified cost. period of time. The concept of “time value” reflects the fact that capital present is more valuable than a similar amount of money received in the future. Its calculation is based on present value, composition and discounting techniques [3], which can be calculated according to the formulas: PV = FV (1 + r)-t (1) FV = K (1 + i) t (2) Where: PV = present value, FV = future value of capital, K = annual cost, r = discount rate, i = inflation rate, t = analysis period. Net Present Value (NPV) NPV is a variation of WLCC where the PV of the cash flow is subtracted...... middle of paper ......ars is used as the typical life of lighting equipment. The results of this study are expressed in terms of recovery period (RP). For each system and each location, the PB curves use electricity prices ranging from 10p/kWh to 50p/kWh. The median electricity price in EU-27 countries in 2009 is 14.01 pence/kWh, which has increased by some 46% in 5 years [7]. The BP shows the annual change in system and electricity prices. Works cited Boussabaine H. & Kirkham R. (2004). Full Life Cycle Costing, Risks and Risk Responses, Blackwell Publishing Ltd. European Commission (2010). Targeted statistics (available at: http://epp.eurostat.ec.europa.eu/portal/page/portal/publications/collections/sif_dif/sif). Mayhoub M. & Carter D. (2009). Hybrid lighting systems: a feasibility study for Europe, as part of the 11th LuxEuropa, Istanbul, Türkiye, 1, 265-272.