Umthamo ngumthamo opheleleyo wombane onokugcinwa yibhetri yelanga, ulinganiswa ngeekilowatt-yure (kWh). Uninzi lweebhetri zelanga zasekhaya ziyilelwe ukuba "zibekeke," okuthetha ukuba unokubandakanya iibhetri ezininzi kunye nenkqubo yakho yokugcina amandla elanga kunye ne-solar ukuze ufumane umthamo owongezelelweyo.
Ngelixa umthamo ukuxelela ukuba inkulu kangakanani ibhetri yakho, ayikuxeleli ukuba ungakanani umbane onokuthi unikwe yibhetri ngexesha elithile. Ukufumana umfanekiso opheleleyo, kufuneka kwakhona uqwalasele ubungakanani bamandla ebhetri. Kwimeko yeebhetri zelanga, ukulinganiswa kwamandla ngumlinganiselo wombane onokuthi uhanjiswe yibhetri ngexesha elinye. Ilinganiswa ngeekilowathi (kW).
Ibhetri enomthamo ophezulu kunye nomlinganiselo ophantsi wamandla unokuzisa umthamo ophantsi wombane (owanele ukuqhuba izixhobo ezimbalwa ezibalulekileyo) ixesha elide. Ibhetri enomthamo ophantsi kunye nomlinganiselo wamandla aphezulu unokuqhuba ikhaya lakho lonke, kodwa kuphela iiyure ezimbalwa.