SOLAR QUESTIONS

BZH36YX
BZH36YX Registered Users Posts: 3
edited May 2017 in Solar Beginners Corner #1
I have been approached by Vivint Company to install solar power.  I have so many questions. 

First of all, where does the solar energy get stored if you have many days of sun?  Do you get a credit if you don't use it all?  Is a battery necessary?  The salesman told me that I don't have to get a battery. 

If my questions seem too elemental it is because I know nothing about it and I don't want to go in blind, if I do decide to go ahead.

Help!!

Comments

  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Usually you would approach a salesman. If you have been approached, I would just tell them I wasn't interested.

    Without batteries, and assuming you are in the United States, It can be a good hedge against increasing energy costs if you can get a long term commitment from the power company for net metering, or if you are in an area that still pays a tariff for renewable energy. These are becoming more rare and some states not longer do 'net metering'. This would also assume a reasonable installation cost. I haven't looked recently but guess somewhere around $2-2.50 a watt installed.

    A grid connected system pushes energy into the grid and helps supply energy for your neighbors, when the sun is shining and you are producing energy, when it's cloudy or night and you are producing less energy than you need it draws energy from the grid. In this manner, no batteries are required.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • BZH36YX
    BZH36YX Registered Users Posts: 3
    Thank you for your response.  I get electricity through PECO now.   PECO controls the grid so I guess they would be the ones to extend to me net metering.  The solar company told me that they would be issuing the bills and said nothing about credits for unused energy or that I might get a bill from PECO.    So I guess I will have to contact PECO and see how this all will work for me.  Thank you for the warning about unsolicited salesmen.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    @ Photowhit said  Usually you would approach a salesman. If you have been approached, I would just tell them I wasn't interested.

    If someone approaches you to buy into something it's generally in their interest not yours, involving substandard equipment, workmanship and a gaurentee too good to be true. Confidence artist prey on the naive and ignorant all the time, good thing you asked before falling for the tactics. Was there a limited time special low low introductory price, theropudic group meetings now forming, call us direct, call us collect, but call us today, kind of approach to their sales tactics? 

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    PECO, formerly the Philadelphia Electric Company.... (from Google).

    At this point, It sounds like PECO has some issues with Grid Tied solar power systems (slow to connect, excuses why customers cannot connect, extra fees after the fact to upgrade PECO equipment before connecting, etc.):

    http://www.philly.com/philly/business/A-dark-cloud-over-solars-sunny-prospects.html

    Vivint appears to be an alarm and home automation company that also does solar. There would be a good chance that they will try and get you to install some of their other systems too--Which can have (what appear to be) pretty high monthly charges... If this website is correct:

    http://www.highya.com/vivint-reviews
    Activation fees start at $99 for home security, $149 for energy management, and $199 for home automation, though yours may be higher depending on your credit rating. Once your Vivint system is installed, monitoring charges range between $49.99 and $68.99 per month, depending on which package you’ve chosen.
    And, there are supposed to be no cancellation charges--But given the above setup, I would expect there would be a several year contract and cancellation charges if you try to end the system before the contract expires.

    You asked about how grid tied solar works... There are solar cells connected to solar to AC utility power adapters (called "grid interactive" or "grid tied" AC inverters). These black boxes take the electrical energy from the solar array and convert it to the 120/240 VAC 60 Hz utility power and connect through your main electrical panel to your utility power.

    The elecrtricity is used inside your home by your lights, refrigerator, etc. -- You cannot even tell the difference inside your home with GT Solar power. The only thing the solar power does is slow down your electric meter--And on bright sunny days, it can "turn your meter backwards". In PECO's case--It looks like you may install a second meter. One for your home and second for solar power. Basically the second meter from the solar power is deducted from your normal utility bill. If your bill was $150 for electricity, you may get a $30-$60 credit during the winter and a $60-$120 credit during the summer (made up numbers as an example--depends on your power usages, how big a system you have, and PECO's actual rate plan and billing setup).

    Where the the "extra power go"--The power actually flows backwards out the the utility line and is "mixed" with normal utility power--And is usually consumed by your neighbors (the utility "buys" your excess production and sells it to the nearby homes).

    Electrically, your utility looks very much like a giant AC Battery bank to your home solar+power system (the utility does not use batteries, it just uses giant AC electrical generators and your tiny amount of electrical energy just looks like a small reduction in electrical power generated by the power plant).

    As said above, do not do anything right now until you understand your home energy usage. Look at your electrical bills and figure out how much electricity (kWatt*Hours per month, $ per month, any natural gas/propane/oil cost you may have per month, etc.) and figure out how much physical energy you actuall use by month.

    In general, conservation is a good place to start. Is your refrigerator old, is your Heating/Airconditioning system old, is your house drafty, have you converted your lighting to LED/Florescent bulbs. Do you have an electric water heater, etc.?

    In general, electric companies do not like GT Solar... And as years go on, utilities and state PUC (public utility commissions) are reducing the subsidies that GT System owners receive. Years ago, my system cost me ~$0.10 per kWH to produce energy (after I got a $10,000 check from the State of California and a 30% federal tax credit). I paid $5 a month for my monthly power bill (electrical) and bought electricity at basically $0.09 per kWH and solar my electricity at $0.20 per kWH. Today, there are some utilities where a GT system pays $20 to $48 or more per month connection power and sell their electricity at $0.06 per kWH and buy electricity at $0.10-$0.30 per kWH. In some states, GT solar has become "illegal" (Hawaii) or just not economically viable (Nevada).

    If you are doing GT solar to save money--Look at energy conservation in your home first--You can probably save 25-50% off your electric bill (if you have never done conservation before).

    It is still possible that GT Solar can save you money on your power bill--But it is a big upfront cost ($15,000+) or you sign a multi-year lease agreement (and save less money).

    We are approaching the end of the "green energy" GT solar fad. It has raised electrical costs for other customers that cannot afford to install solar or live in houses where it cannot be installed (trees, power lines, no south facing roof, etc.) or they are renters (do not own the property) and such... And GT solar is starting to negatively affect the costs (and profits) of utility companies (and even reduce state tax collections too).

    If you are still interested in solar power--You need a roof (or yard space) where you can install a bunch of solar panels in full sun. If you have shading (trees, chimeny, dormers, neighbors, etc.) that cut your 9am to 3pm (optimum sun hours), it may not be practical to install a solar gt system. Solar panels only work (well) in full sun. Any little bit of shading (even shadows from power lines) can reduce the output power by a lot (upwards of 50% or more--depending on system type and amount of shading).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BZH36YX
    BZH36YX Registered Users Posts: 3
    Thank you Bill for your analysis.  It is very helpful.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    I should also add, in general, solar panels plus gt inverter means if utility power fails, your gt inverters shut down too.

    If you want/need backup power, you need different inverters and a large battery bank (plus possibly a back up generator).

    Many gt solar installers "skip over" no backup power capabilities part of the sales pitch.

    - Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MikeBloom
    MikeBloom Registered Users Posts: 3
    edited May 2017 #8
    I am sure that you have been approached to install a grid tie system. If that is the case it is unlikely the installer would include battery back-up. It is true that if PECO has an outage that you will not have electricity - but it also isn't really important unless you experience a lot of outages.  We experience an outage once every several years - not quite worth the expense for battery back-up for us.

    It also sounds like they are offering you a lease rather than a sale.  DO NOT DO A LEASE.  This is a terrible financial solution.  If you install solar, pay for it yourself and finance it yourself.  I would recommend a home equity line of credit or, if that is not available to you, a PACE loan (interest rates are definitely higher but no income verification).  

    You can estimate evaluate your historical electricity costs, compare to how much electricity you will save and estimate the reduction in your bill.  Then you can compare to the cost of financing through your HELOC or PACE loan.  You might find that your payback is immediate - i.e. that the cost of financing is less than the abated electricity cost.  This is true for my situation.  

    Don't forget that you will receive a tax credit for 30% of the costs associated with installing solar.  

    I am sure that PECO has a well developed program for net metering, I wouldn't be terrible concerned about that.

    Higher capacity panels are good on rooftops with shading issues.  1) they reduce the amount of rooftop required, so you can avoid shady areas, and 2) when in the sunlight they produce more electricity.  However, typically they are much more expensive per watt.  You will need to do the math.

    However, you may find that it doesn't make sense to abate 100% of your electricity needs.  For example, if you have tiered electricity costs and freqently consume into the higher tiers, you may get significant pay-off just by getting out of those tiers.  Completely eliminating your energy requirements may not be cost effective.  

    Finally, consider whether whatever system you install is expandable - if you undersize your system now you might want to increase it later. Its a lot easier if you build in that flexibility now.  For example, if you use string inverters, upsizing the module for future capacity is relatively modest additional cost.  If you use micro-inverters, generally they are readily expandable. 

    Good luck.