New to matlab and trying to model a hot water storage tank that buys electricity when the price is low and uses it later to meet the demand. So in a perfect scenario 100% of the demand would be stored or purchased when the cost is low. The heater can produce Q_hph, which can either be sent to meet demand Q_hphj or it can be sent to the tank Q_teshin. Q_hph can be greater than the demand (Q_demh) but Q_demh==Q_hphj+Q_teshout, where Q_teshout is what leaves the tank.
When I run the optimization, Q_hph always returns 0 and Q_teshout=Q_demh, which shouldn't be the case without first having a value for Q_teshin.
Thanks in advance for any help!