Services for technical design of photovoltaic systems, especially including technical calculations, especially with regard to current and power calculations; dimensioning of charge regulators and power inverters; simulations of photovoltaic systems with regard to operation and with regard to weather dependant production of electrical power; mechanical calculations of support frames and mounting systems, especially considering wind load and snow load at the installation site; technical services of monitoring and controlling the power and output of photovoltaic devices and systems built thereof