= Target = Power a 12V/2A (24W) system for 24h/24h, using an autonomous solar system in the Netherlands (read: not very sunny). = Initial thought = {{{ 24W * 24h =~ 0.6kW and 2A * 24h = 48.0Ah }}}, so given ourself a {{{100 Ah}}} battery (AGM, deep-cycle), should last us to roughly 2 days of operation. After first measurements my 20W Solar panel is preforming {{{50%}}}} less if I put it a bit into the shadow (balcony fences). Putting it into fully into the sun makes it generate roughly 1.2A/12V which is indeed [http://humietrading.nl/index.php?option=com_content&task=blogsection&id=5&Itemid=34 as advertised]. The input should run at {{{17.5V}}} to make it take the full {{{20W}}}. The change controller [http://www.stecasolar.com/index.php?Steca_Solsum_F_en Steca Solsum 6.6F] seems to regulate the input to {{{12V}}}, leaving me wondering if the panel will be fully utilized. Cause {{{20W/14W * 100% = 70%}}} e.g. loosing {{{30%}}} efficiency seems a bit to much. = Idea/Brainstorm = * Use [http://www.geo-dome.co.uk/article.asp?uname=solar_mirror mirrors] to increase efficiency. * Measure DC current with an [http://openenergymonitor.org/emon/node/31 LT1495 and Arduino].