comparing panels for bids given

I have recieved bids from three companies who have given me multiple options.

Suntech 275 watt stp275-24/vd panels with SMA6000 inverter @ 5.8 cents DC watt installed

Sharp 235 watt Nu-U235F4 panels with enphase 215 inverters @ 6.7 cents DC watt installed

Sunpower SPR230Ewht-d panels with enphase 210 inverters @ 8 cents DC watt installed.


These are all ground mount quotes. The DC watt cost is before any rebates, tax credits etc.
and are for systems that range from 18 to 24 panels depending on current or projected uses. For example the 18 panel or 24 panel sharp 235 system both came out to 6.7 cents DC watt installed. The same ration hold true for the other quotes.

Needless to say I am a newbie. All opinions would be welcome, especially on the Panel choices that are offered in the quotes. I do have a bit of shading problems in the fall and winter months so I understand the sma-enphase differences in both operation and cost.

thanks in advance for any input.

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: comparing panels for bids given

    If the inverters are included in the options, shouldn't the price be on AC Watts? Otherwise you're including the inverter component in the price but not in the Watts.

    I don't do grid-tie, but even off-grid we look at the AC power potential when figuring everything out (unless it's a DC-only system).
  • System2
    System2 Posts: 6,290 admin
    Re: comparing panels for bids given

    dc watts should be dollars not cents .. sorry ..

    ac numbers on the gross cost were

    sharp 235 enphase 215 = 7.70 installed

    sunpower 230 enphase 210 = 9.27 installed

    suntech 275 sma sb6000 = 6.75 installed


    my main reason for posting is quality - reliabilty of the three panels

    thanks again
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: comparing panels for bids given

    Nothing wrong with any of the equipment listed. Sunpower panels are positive ground, which creates issues off-grid but shouldn't be a problem with G-T systems.

    If you have no shading issues the Enphase microinverters don't offer much advantage other than net monitoring and some debatable install ease.

    I've had good experience with Sharp panels, not to detract from the others.

    Based on the info given, I'd pick the Suntech & SMA set up. Others (especially those who deal with grid-tie) may have different opinion.