===== Sand Battery =====

2x3 = 6m2

hustota = 1500 kg/m3
thermal_capacity = 800 J/kg.m3.C

Ak by sme chceli ohriat o 100 stupnov\\
= ''6 x 1500 x 800 x 100'' = **720 000 000 J** = 720 000 KJ = 200 kWh (200x0.15 EUR = 30EUR)

Ak by som mal ''4 panely'' s vykonom ''200W'' a slnko by svietilo ''4 hodiny denne''

to by bolo ''800wh x 4 denne'' = ''2400wh'' = ''2.4kwh'' = ''2.4 x 3600'' = **8 640 KJ**. Takyto pieskovy kvader by som za 1 den ohrial o ''6 x 1500 x 800 x D = 8 640 KJ'' z toho ''D = (6 x 1500 x 800 / 8640000)'' a to je **0.83 stupna Celzia**, kde D je teplotny rozdiel.