22 Sales & System Economics Practice Questions & Answers

1. 1. A proposal describes a 7.2 kW-dc array estimated to produce 10,400 kWh in its first year, on a rate billed at $0.19 per kWh. When the utility calculates the energy charges on the customer's monthly bill, which quantity is it actually billing?

   • A.The dc kilowatt capacity rating printed on the proposal
   • B.The kilowatts of inverter capacity approved at interconnection
   • C.The maximum instantaneous kilowatts the array delivers
   • D.The kilowatt-hours the meter records over the billing period✓ Answer

   Kilowatts measure power, an instantaneous rate, while kilowatt-hours measure energy, which is power accumulated over time; the residential energy charge is energy price multiplied by the kilowatt-hours the meter records. The kW rating describes capacity and governs equipment and interconnection review, and kW appears on a bill only where a demand charge applies, which is normally a commercial arrangement.

   Source: NABCEP PV Associate job task analysis, sales and economics: preliminary system estimate and utility rate structures (energy versus power billing)Report a problem with this question

2. 2. A customer used 12,000 kWh over the past year. For this location the estimator assumes a well-oriented array will produce about 1,500 kWh per year for each kW-dc installed. Ignoring any future change in usage, roughly what array size matches that annual consumption?

   • A.About 12 kW-dc, matching one kW for each 1,000 kWh used
   • B.About 18 kW-dc, found by multiplying 12,000 kWh by 1.5
   • C.About 6 kW-dc, because half of the load is served at night
   • D.About 8 kW-dc, found by dividing 12,000 kWh by 1,500 kWh per kW✓ Answer

   Annual energy divided by the assumed annual energy per unit of capacity yields capacity: 12,000 kWh divided by 1,500 kWh per kW-year is 8 kW-dc. The specific yield varies widely with location, orientation and shading, so it must be stated as an assumption rather than treated as a fixed constant, and night-time consumption does not reduce the size needed because annual production is netted against annual consumption.

   Source: NABCEP PV Associate job task analysis, sales and economics: preparing a preliminary system estimate from customer energy usageReport a problem with this question

3. 3. During qualification a customer mentions that an electric vehicle will be purchased in a few months. How should that affect the preliminary system estimate?

   • A.Reduce the size, since an EV shifts load into off-peak hours
   • B.Size to last year's bills and sell a second array later on
   • C.Ignore it, because sizing must be based on metered history
   • D.Add the expected charging load before sizing the array✓ Answer

   A preliminary estimate is built on anticipated consumption, not only on metered history, because a new charging load, heat pump, pool or addition can change annual kilowatt-hours substantially. Sizing to last year's bills alone leaves the customer short of the offset they were sold; note also that many utilities limit system size relative to documented consumption, so anticipated load may need to be supported with evidence.

   Source: NABCEP PV Associate job task analysis, sales and economics: current and anticipated customer energy usageReport a problem with this question

4. 4. Twelve months of billing history show consumption roughly doubling in July and August and falling back in spring and fall. What does this pattern most likely indicate about the household?

   • A.The customer already exports surplus energy in summer months
   • B.Electric space heating drives most of the annual consumption
   • C.Air conditioning is the largest seasonal load in the home✓ Answer
   • D.The meter is misreading and the utility should be asked to test it

   A summer-peaking profile points to cooling, because air conditioning runs hardest in the hottest months, while a winter-peaking profile usually points to electric space heating or an electric water heater in a cold climate. Reading a full twelve months rather than a single bill is what makes the seasonal shape visible, and that shape drives both the sizing conversation and the discussion of when energy is worth most.

   Source: NABCEP PV Associate job task analysis, sales and economics: customer usage profile, daily and seasonal patternsReport a problem with this question

5. 5. Which pair of items is essential to collect before preparing a proposal and a contract for a residential prospect?

   • A.Recent utility bills and confirmation of who owns the property✓ Answer
   • B.The customer's credit score and the household's tax bracket
   • C.A roof drawing and the brand of equipment the customer prefers most
   • D.The number of occupants and the age of the home's appliances

   The utility bill identifies the serving utility, the rate schedule, the account used for interconnection, the annual kilowatt-hours and the blended price per kilowatt-hour, so it is the single most useful qualifying document. Ownership must be confirmed separately because only the titleholder can authorize work and sign a contract; renters, condominium and homeowner-association properties and tenant-occupied commercial buildings require the owner's participation.

   Source: NABCEP PV Associate job task analysis, sales and economics: critical information to qualify a customer, including utility information and property ownershipReport a problem with this question

6. 6. A modelling tool reports a first-year production figure for a proposed array. How should that figure be presented to the customer?

   • A.As a value certified by the utility during interconnection review
   • B.As a minimum output that the installer contractually guarantees
   • C.As an exact annual total the array will repeat every year
   • D.As an estimate that depends on weather and stated assumptions✓ Answer

   Production models run on typical weather data and on assumptions about orientation, shading, soiling and losses, so the output is a probabilistic estimate that real years will fall above and below. Presenting a modelled number as a guarantee misrepresents it; a guarantee exists only where a separate written production guarantee is offered, and the assumptions behind the estimate should be disclosed with it.

   Source: NABCEP Code of Ethics and PV Associate job task analysis, sales and economics: ethical representation of expected energy productionReport a problem with this question

7. 7. A customer is told the proposed system will offset essentially all of the home's annual kilowatt-hour consumption. What should the salesperson explain about the customer's future utility bills?

   • A.Fixed monthly charges and minimum bills continue regardless of output✓ Answer
   • B.The utility will refund the fixed charges at the annual true-up
   • C.Only the interconnection fee remains after the meter is changed
   • D.The bills will stop once the system is energized and approved

   Offset describes only the energy portion of the bill, while customer charges, minimum bills and any standby or interconnection charges are levied for being connected to the grid and are not reduced by production. A customer who is promised a zero bill and then receives one every month has been misled, so the persistence of fixed charges must be disclosed during the sale.

   Source: NABCEP PV Associate job task analysis, sales and economics: cost of utility electricity and rate structure componentsReport a problem with this question

8. 8. Under full retail net metering an exported kilowatt-hour is credited at essentially the retail price. If a utility instead pays a lower avoided-cost rate for exports while imports are still billed at retail, what changes about the project economics?

   • A.The utility waives the fixed monthly charge as compensation
   • B.Exported energy becomes worth more than the energy consumed on site
   • C.Energy used on site gains value relative to exported energy✓ Answer
   • D.The timing of production stops affecting the customer's savings

   When exports earn less than imports cost, every kilowatt-hour consumed at the moment it is generated avoids the full retail price, while a kilowatt-hour sent to the grid earns only the lower export rate, so self-consumption and load shifting carry more value and storage becomes easier to justify. The specific credit rules, rate values and true-up terms are set by the utility and the jurisdiction and must be confirmed for the customer's own account.

   Source: NABCEP PV Associate job task analysis, sales and economics: net metering and other export compensation and revenue opportunitiesReport a problem with this question

9. 9. A customer is served under a time-of-use rate whose highest prices fall in the late afternoon and early evening. Compared with a flat rate, what changes about the value of the array's output?

   • A.Every kilowatt-hour produced carries the same value all day
   • B.Output produced during the priced peak hours is worth more✓ Answer
   • C.A due-south array always outperforms one facing west on this rate
   • D.Total annual kilowatt-hours become the only figure that matters

   A time-of-use rate prices energy differently by hour and season, so when the array produces matters as much as how much it produces in a year. This is why a west-facing array, which shifts output later into the afternoon, can be worth more per kilowatt-hour than a slightly higher-yielding south-facing array on such a rate, and why storage that discharges into the peak window adds value; the actual periods and prices are set by the utility.

   Source: NABCEP PV Associate job task analysis, sales and economics: utility rate structures including time-of-use pricingReport a problem with this question

10. 10. A commercial customer's electric bill includes a demand charge. What is that charge based on, and what does adding PV alone do to it?

    • A.The highest measured kilowatt demand; PV may not reduce it reliably✓ Answer
    • B.The rated size of the electrical service; PV lowers it after inspection
    • C.The average monthly load in kilowatts; PV always cuts it sharply
    • D.Total monthly kilowatt-hours; PV removes it in proportion to output

    A demand charge is billed in dollars per kilowatt on the highest demand interval recorded during the billing period, not on total energy, so a single brief peak sets the charge for the whole month. Because that peak can occur after sunset or under heavy cloud, PV by itself may cut energy charges substantially while barely touching the demand charge; storage or demand-limiting controls are what address it.

    Source: NABCEP PV Associate job task analysis, sales and economics: utility rate structures including demand chargesReport a problem with this question

11. 11. A twenty-five-year savings projection is being prepared for a customer. Which pair of effects should be built into the later years of that projection?

    • A.Production constant plus a single cleaning in the final year
    • B.Gradual decline in module output plus a likely inverter replacement✓ Answer
    • C.Declining utility rates plus a free warranty exchange at year ten
    • D.Rising module output plus falling maintenance costs over time

    Crystalline modules lose a small fraction of their output every year, commonly on the order of half a percent, so a late-life year produces measurably less than the first year and saves correspondingly less. Power electronics are the usual mid-life replacement item and their cost belongs in the cash flow, along with monitoring and any service contract, which is why year-twenty-five savings are lower than year-one savings.

    Source: NABCEP PV Associate job task analysis, sales and economics: equipment degradation and replacement, and maintenance costsReport a problem with this question

12. 12. A system costs $21,000 after all up-front incentives are applied. In its first year it is expected to offset 9,000 kWh at a blended rate of $0.20 per kWh. Using simple payback, what does the proposal show?

    • A.About 11.7 years, cost divided by annual dollar savings✓ Answer
    • B.About 23.3 years, cost divided by half the annual savings
    • C.About 2.3 years, cost divided by annual kilowatt-hours
    • D.About 5.8 years, cost divided by twice the annual savings

    Simple payback is net installed cost after incentives divided by first-year savings in dollars: 9,000 kWh times $0.20 is $1,800 per year, and $21,000 divided by $1,800 is about 11.7 years. Dividing by kilowatt-hours rather than dollars mixes units and is the classic error; simple payback also ignores rate escalation, degradation, maintenance and the time value of money, so it is a screening figure rather than a full analysis.

    Source: NABCEP PV Associate job task analysis, sales and economics: years to payback and return on investment calculationsReport a problem with this question

13. 13. What does the levelized cost of energy for a proposed PV system express, and what is it compared against?

    • A.The cost per kilowatt-hour over the system life, against the utility rate✓ Answer
    • B.The first-year saving per kilowatt, against the demand charge billed
    • C.The annual saving per dollar invested, compared with bank interest
    • D.The installed price per watt, compared with the other bids received

    Levelized cost of energy divides the total lifetime cost of owning and running the system, including maintenance and expected replacements and net of incentives, by the total kilowatt-hours it is expected to produce, giving a price per kilowatt-hour. Because it is expressed in the same units as the utility rate, it is the apples-to-apples comparison: the project is attractive when the levelized cost sits below the rate the system displaces.

    Source: NABCEP PV Associate job task analysis, sales and economics: lifecycle cost of energy compared with the cost of utility electricityReport a problem with this question

14. 14. A twenty-five-year savings figure in a proposal assumes utility rates rise five percent every year. How should this assumption be handled with the customer?

    • A.Raise it until the projected savings cover the loan payment
    • B.Leave it out of the paperwork so the numbers look simpler
    • C.Present it as a rate the utility has committed to for the term
    • D.Disclose it as an assumption and base it on historical data✓ Answer

    No utility commits to a future rate path, so an escalation rate is an assumption whose effect compounds heavily over a long projection and can double or halve the headline savings figure. Ethical practice is to state the assumption in writing, support it with the utility's own rate history, and show the customer how the result changes if rates rise more slowly.

    Source: NABCEP Code of Ethics and PV Associate job task analysis, sales and economics: ethical utility escalation assumptions based on historical dataReport a problem with this question

15. 15. A customer is comparing a solar lease with a power purchase agreement offered by the same provider. What is the essential difference in how the customer pays?

    • A.The lease charges per kilowatt-hour and the PPA charges a flat fee
    • B.Both charge a fixed amount, but the lease term is always longer
    • C.Both charge per kilowatt-hour, but the PPA adds a yearly service fee
    • D.The lease charges a set monthly amount, the PPA per kilowatt-hour produced✓ Answer

    A lease is a payment for the use of equipment, so the amount is set in advance and does not move with how much the array actually generates, while a power purchase agreement is a payment for energy delivered, so a weak production year lowers the payment and the production risk sits with the owner. Both are third-party ownership arrangements and both usually contain an annual escalator that should be compared with a realistic view of utility rate increases.

    Source: NABCEP PV Associate job task analysis, sales and economics: financing options, lease and power purchase agreementReport a problem with this question

16. 16. Under a lease or a power purchase agreement, a third party owns the equipment installed on the customer's roof. Who is entitled to claim the tax benefits associated with owning that system?

    • A.The parties split them according to the monthly payment
    • B.The third party that owns the system, not the customer✓ Answer
    • C.The homeowner, because the system sits on the homeowner's roof
    • D.The utility, because it accepts the exported energy from it

    Tax benefits attach to ownership of the equipment, so in a third-party arrangement the owner takes them and reflects their value in the price it quotes the customer; the customer buys a payment stream, not an asset. This is also why hosts with little or no tax liability, such as non-profits and public agencies, have historically used third-party structures, and why the customer should be sent to a tax professional rather than given a tax opinion by the salesperson.

    Source: NABCEP PV Associate job task analysis, sales and economics: types of incentives and third-party ownership financingReport a problem with this question

17. 17. A customer who cannot pay cash is considering a solar loan instead of a lease. Which statement describes the loan accurately?

    • A.No interest is charged because the system itself is the collateral
    • B.The customer owns the system and pays interest over the term✓ Answer
    • C.The customer gives up ownership benefits but avoids interest
    • D.The lender owns the system until the customer makes the last payment

    A loan finances a purchase, so title to the equipment passes to the customer at installation and the customer keeps whatever incentives and added property value ownership carries, while repaying principal plus interest. A lender may record a lien or a security interest against the equipment, but that is security for repayment and does not make the lender the owner; the salesperson should compare rate, term, down payment and any fee folded into the cash price.

    Source: NABCEP PV Associate job task analysis, sales and economics: financing options, cash purchase and loanReport a problem with this question

18. 18. A customer asks how property assessed financing for a solar system is repaid and what happens if the home is sold. What is the accurate description?

    • A.It is repaid monthly to the installer and ends when the house is sold
    • B.It is repaid through an assessment tied to the property itself✓ Answer
    • C.The utility repays it and adds the amount to the customer's rate
    • D.It is repaid out of the export credits the utility issues yearly

    This form of financing is repaid as an assessment collected with the property tax bill, so the obligation attaches to the real property rather than to the individual borrower and generally rides with the property at sale. Because the assessment is a senior, lien-based obligation it can complicate a refinance or a closing, and availability, terms and consumer protections differ by program and jurisdiction, so the local program rules must be checked.

    Source: NABCEP PV Associate job task analysis, sales and economics: financing options including property assessed financing and other loansReport a problem with this question

19. 19. A homeowner with a third-party-owned system decides to sell the house. What should the salesperson have disclosed at signing about this situation?

    • A.The provider removes the system at no cost before the closing
    • B.The agreement must be assumed by the buyer, bought out, or transferred✓ Answer
    • C.The remaining payments are forgiven when the sale is recorded
    • D.The agreement ends automatically when the title changes hands

    A lease or power purchase agreement is a long-term contract on equipment the seller does not own, so it does not disappear at closing: the buyer must qualify and assume it, the seller must buy the system out under the contract's schedule, or the provider must approve some other transfer. Because this regularly complicates a sale, the buyout schedule and the transfer and assignment terms belong in the disclosure conversation before signing.

    Source: NABCEP PV Associate job task analysis, sales and economics: financing options and contract disclosure at transfer of propertyReport a problem with this question

20. 20. A customer asks what protects them if the modules produce less than promised as the years pass. Which warranty addresses that specifically?

    • A.The roof warranty held by the original roofing contractor
    • B.The workmanship warranty covering the installer's own labour
    • C.The performance warranty covering output levels over time✓ Answer
    • D.The product warranty covering defects in manufacturing

    The three warranties do different jobs: workmanship covers the installer's labour and installation defects, the product warranty covers physical defects in the module itself, and the performance or power warranty promises that output stays above a declining threshold across the years. A performance claim is therefore about degradation rather than breakage, and labour to diagnose or replace is usually covered only by the installer's workmanship warranty, whose value depends on that company still being in business.

    Source: NABCEP PV Associate job task analysis, sales and economics: warranty limitations, equipment versus workmanship coverageReport a problem with this question

21. 21. At a kitchen-table appointment the customer asks whether a tax incentive will apply to their situation, whether the roof framing can carry the array, and what the local permit will require. What is the professional response?

    • A.Refer them to a tax advisor, a structural engineer, and the AHJ✓ Answer
    • B.Answer the tax and structural parts and skip the permit question
    • C.Answer all three from experience so the customer can sign tonight
    • D.Tell the customer that none of these affect the proposal price

    Whether an incentive helps a particular household depends on that household's own tax position, structural adequacy is a licensed engineering judgement, and permit requirements are set by the authority having jurisdiction and vary from place to place, so none of the three can be answered responsibly from sales experience. Referring each question to the right professional protects the customer and the company, and pressing for a signature that evening is exactly the pressure tactic ethical practice forbids.

    Source: NABCEP Code of Ethics: working within one's scope of competence and referring questions to qualified professionals and the authority having jurisdictionReport a problem with this question

22. 22. During the site visit the customer mentions that the roof covering is near the end of its service life. Why does this matter to the economics of the proposal?

    • A.The age of the roof covering voids the module product warranty
    • B.The utility will not interconnect a system on an older roof
    • C.It changes the array's orientation and therefore its annual output
    • D.The array would later have to be removed and reinstalled at extra cost✓ Answer

    If the remaining life of the roof covering is shorter than the life of the array, the customer will pay to remove and reinstall the system when the roof is replaced, and that cost belongs in the cash-flow shown at the sale rather than being discovered years later. Re-roofing first usually costs less overall and avoids disputes about roof warranty coverage, which is why roof type, age and condition are captured during qualification.

    Source: NABCEP PV Associate job task analysis, sales and economics: site information at estimate stage and roofing replacement as a maintenance costReport a problem with this question

Practice questions based on the published knowledge domains of the NABCEP PV Associate Job Task Analysis and on standard photovoltaic engineering and safety references. NABCEP is not affiliated with this site and does not endorse it. Answers here deliberately avoid code dimensions, manufacturer specifications, incentive rules and prices, all of which change and vary by jurisdiction — always apply the electrical and building codes adopted by the authority having jurisdiction, the equipment manufacturer's instructions, and your employer's safety program. Confirm current exam requirements with NABCEP before testing. About the NABCEP Associate program →