| Summary of Significant Accounting Policies | 3. Summary of Significant Accounting
Policies
(a) Basis of Presentation The accompany consolidated financial
statements of the Group are prepared in conformity with accounting principles generally accepted in the United States of America (“U.S.
GAAP”). The accompany consolidated financial
statements have been prepared on a going concern basis, which contemplates the realization of assets and the satisfaction of liabilities
in the normal course of business. The realization of assets and the satisfaction of liabilities in the normal course of business are dependent
on, among other things, the Group’s ability to operate profitably, to generate cash flows from operations, and to pursue financing
arrangements to support its working capital requirements.
(b) Principles of Consolidation The consolidated financial statements
include the financial statements of the Group, and its subsidiaries. All material inter-Group transactions and balances have been eliminated
upon consolidation. For consolidated subsidiaries where the Group’s ownership in the subsidiary is less than 100%, the equity interest
not held by the Group is shown as noncontrolling interests. The Group accounts for investments over which it has significant influence
but not a controlling financial interest using the equity method of accounting. The Group deconsolidates a subsidiary when the Group ceases
to have a controlling financial interest in the subsidiary. When control is lost, the parent-subsidiary relationship no longer exists
and the parent derecognizes the assets and liabilities of the subsidiary.
(c) Use of Estimates The preparation of the financial
statements in conformity with U.S. GAAP requires the Group to make estimates and assumptions that affect reported amounts of assets
and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements as well as
the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Significant accounting estimates reflected in the Group’s consolidated financial statements include the allowance made for
credit losses, inventory write-downs, the estimated useful lives of long-lived assets, the impairment of goodwill, long-lived assets and
project assets, fair value of derivative liability and warrants, valuation allowance of deferred tax assets, accrued warranty
expenses, the grant-date fair value of share-based compensation awards and related forfeiture rates, the lease discount rate, the
purchase price allocation in acquisition, and fair value of financial instruments. Changes in facts and circumstances may result in
revised estimates. The current economic environment has increased the degree of uncertainty inherent in those estimates and
assumptions.
(d) Foreign Currency Translation and Foreign Currency Risk The functional currency of the Group
and subsidiaries located in the United States is the United States dollar (“US$” or “$”). The functional currency
of the Group’s subsidiaries located in the PRC, Europe, United Kingdom, Japan, Canada and Australia are Renminbi (“RMB”),
EURO (“EUR”), British Pounds(“GBP”), Japanese Yen (“JPY”), Canadian Dollar (“CAD”) and
Australia Dollar (“AUD”), respectively. Transactions denominated in foreign currencies are re-measured into the functional
currency at the rates of exchange prevailing when the transactions occur. Monetary assets and liabilities denominated in foreign currencies
are re-measured into the functional currency at rates of exchange in effect at the balance sheet dates. Exchange gains and losses are
included in the consolidated statements of operations. The Group’s reporting currency
is the US$. Assets and liabilities of subsidiaries, whose functional currency is not the US$, are translated into US$ using exchange rates
in effect at each period end, and revenues and expenses are translated into US$ at average rates prevailing during the year, and equity
is translated at historical exchange rates, except for the change in retained earnings during the year which is the result of the income
or loss. Gains and losses resulting from the translations of the financial statements of these subsidiaries into US$ are recognized as
other comprehensive income or loss in the consolidated statement of comprehensive loss.
(e) Fair Value of Financial Instruments The Group measures at fair value certain
of its financial and non-financial assets and liabilities by using a fair value hierarchy that prioritizes the inputs to valuation techniques
used to measure fair value. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly
transaction between market participants at the measurement date, essentially an exit price, based on the highest and best use of the asset
or liability. The levels of the fair value hierarchy are:
Ÿ Level 1 — Quoted market prices in active markets for identical assets or liabilities.
Ÿ Level 2 — Significant other observable inputs (e.g., quoted prices for similar items in active markets, quoted prices for identical or similar items in markets that are not active, inputs other than quoted prices that are observable, such as interest rate and yield curves, and market-corroborated inputs).
Ÿ Level 3 — Unobservable inputs in which there is little or no market data, which require the reporting unit to develop its own assumptions. The Group uses quoted market prices
to determine the fair value when available. If quoted market prices are not available, the Group measures fair value using valuation techniques
that use, when possible, current market-based or independently-sourced market parameters, such as interest rates and currency rates.
(f) Business Combination Business combinations are recorded
using the acquisition method of accounting and, accordingly, the acquired assets and liabilities are recorded at their fair market value
at the date of acquisition. Any excess of acquisition cost over the fair value of the acquired assets and liabilities, including identifiable
intangible assets, is recorded as goodwill. The Group charges acquisition related costs that are not part of the purchase price consideration
to general and administrative expenses as they are incurred. Those costs typically include transaction and integration costs, such as
legal, accounting, and other professional fees. The Group adopted Accounting Standard
Update (“ASU”) 2017-01 “Business Combination (Topic 805): Clarifying the Definition of a Business” on January
1, 2018 and applied the new definition of a business prospectively for acquisitions made subsequent to December 31, 2017. Upon the adoption
of ASU 2017-01, a new screen test is introduced to evaluate whether a transaction should be accounted for as an acquisition and/or disposal
of a business versus assets. In order for a purchase to be considered an acquisition of a business, and receive business combination accounting
treatment, the set of transferred assets and activities must include, at a minimum, an input and a substantive process that together significantly
contribute to the ability to create outputs. If substantially all of the fair value of the gross assets acquired is concentrated in a
single identifiable asset or a group of similar identifiable assets, then the set of transferred assets and activities is not a business.
The adoption of this standard requires future purchases to be evaluated under the new framework.
(g) Asset Acquisition When the Group acquires other entities,
if the assets acquired and liabilities assumed do not constitute a business, the transaction is accounted for as an asset acquisition.
Assets are recognized based on the cost, which generally includes the transaction costs of the asset acquisition, and no gain or loss
is recognized unless the fair value of noncash assets given as consideration differs from the assets’ carrying amounts on the Group’s
books. If the consideration given is not in the form of cash (that is, in the form of noncash assets, liabilities incurred, or equity
interest issued), measurement is based on either the cost to the acquiring entity or the fair value of the assets (or net assets) acquired,
whichever is more clearly evident and, thus, more reliably measureable. The cost of a group of assets acquired in an asset acquisition
is allocated to the individual assets acquired or liabilities assumed based on their relative fair value and does not give risk to goodwill.
(h) Cash and Cash Equivalents Cash and cash equivalents include cash
on hand, cash accounts, interest bearing savings accounts and all highly liquid investments with original maturities of three months or
less, and which are unrestricted as to withdrawal and use. There were no
(i) Restricted Cash Restricted cash represent bank deposits
with designated use, which cannot be withdraw without certain approval or notice. As of December 31, 2021, the Group
had restricted bank deposits of $ 8,080 6,140 1,940 As
of December 31, 2020, the Group had restricted bank deposits of $ 900
(j) Accounts Receivable, net The Group grants open credit terms
to credit-worthy customers. Accounts receivable are primarily related to the Group's sales of pre-development solar projects, sales of
PV components, revenue from roofing and solar energy systems installation, electricity revenue with PPA, and sales and leasing of EVs. The Group maintains allowances for
credit losses for estimated losses resulting from the inability of its customers to make required payments. Accounts receivable is considered
past due based on its contractual terms. In establishing the allowance, management considers historical losses, the financial condition,
the accounts receivables aging, the payment patterns and the forecasted information in pooling basis upon the use of the Current Expected
Credit Loss Model (“CECL Model”) in accordance with ASC topic 326, Financial Instruments - Credit Losses. Accounts receivable
that are deemed to be uncollectible are charged off against the allowance after all means of collection have been exhausted and the potential
for recovery is considered remote. There is a time lag between when the Company estimates a portion of or the entire account balances
to be uncollectible and when a write off of the account balances is taken. The Company takes a write off of the account balances when
the Company can demonstrate all means of collection on the outstanding balances have been exhausted. The Group does not have any off-balance-sheet
credit exposure related to its customers. Contractually, the Group may charge interest for extended payment terms and require collateral.
(k) Inventories Inventories are stated at the lower
of cost or net realizable value. The cost of raw materials is determined on the basis of weighted average cost method.
The cost of finished goods is determined on the basis of weighted average and comprises direct materials, direct labor and an appropriate
proportion of overhead. Net realizable value is based on estimated selling prices less selling expenses and any further costs expected
to be incurred for completion. Adjustments to reduce the cost of inventory to net realizable value are made, for estimated excess, obsolescence,
or impaired balances if any.
(l) Project Assets The Group acquires or constructs PV
solar power systems (“solar system”) that are (i) held for development and sale or (ii) held for the Group’s own use
to generate income or return from the use of the solar systems. Solar systems are classified as either held for development and sale within
“project assets” or as held for use within “property and equipment” based on the Group’s intended use of
solar systems. The Group determines the intended use of the solar systems upon acquisition or commencement of project construction. Classification of the solar systems
affects the accounting and presentation in the consolidated financial statements. Transactions related to the solar systems held for development
and sale within “project assets” are classified as operating activities in the consolidated statements of cash flows and reported
as sales and costs of goods sold in the consolidated statements of operations upon the sale of the solar systems and fulfillment of the
relevant recognition criteria. Incidental electricity income generated from the solar systems held for development and sale prior to the
sale of the projects is recorded in other operating income in the consolidated statement of operations. The solar systems held for use
within “property and equipment” are used by the Group in its operations to generate income or a return from the use of the
assets. Income generated from the solar systems held for use are included in net sales in the consolidated statement of operations. The
costs to construct solar systems intended to be held for own use are capitalized and reported within property and equipment on the consolidated
balance sheets and are presented as cash outflows from investing activities in the consolidated statements of cash flows. The proceeds
from disposal of solar systems classified as held for own use are presented as cash inflows from investing activities within the consolidated
statements of cash flows. A net gain or loss upon the disposal of solar systems classified as held for own use is reported in other operating
income or expense in the consolidated statement of operation. Solar systems costs consist primarily
of capitalizable costs for items such as permits and licenses, acquired land or land use rights, and work-in-process. Work-in-process
includes materials and modules, construction, installation and labor, capitalized interests and other capitalizable costs incurred to
construct the PV solar power systems. The solar systems held for development
and sale, named as “project assets”, are reported as current assets on the consolidated balance sheets when upon completion
of the construction of the solar systems, the Group initiates a plan to actively market the project assets for immediate sale in their
present condition to potential third party buyers subject to terms that are usual and customary for sales of these types assets and it
is probable that the project assets will be sold within one year. Otherwise, the project assets are reported as noncurrent assets. No
depreciation expense is recognized while the project assets are under construction or classified as held for sale. For solar systems held for development
and sale, named as “project assets”, the Group considers a project commercially viable if it is anticipated to be sold for
a profit once it is either fully developed or fully constructed. The Group also considers a partially developed or partially constructed
project commercially viable if the anticipated selling price is higher than the carrying value of the related project assets plus the
estimated cost to completion. The Group considers a number of factors, including changes in environmental, ecological, permitting, market
pricing or regulatory conditions that affect the project. Such changes may cause the cost of the project to increase or the selling price
of the project to decrease. The Group records an impairment loss of the project asset to the extent the carrying value exceed its estimated
recoverable amount. The recoverable amount is estimated based on the anticipated sales proceeds reduced by estimated cost to complete
such sales. Subsequent reversal of a previously recognized impairment loss is prohibited once the measurement of that loss is recognized.
(m) Property and Equipment, net The Group accounts for its property
and equipment at cost, less accumulated depreciation and any impairment. Cost includes the prices paid to acquire or construct the assets,
interest capitalized during the construction period and any expenditure that substantially extends the useful life of an existing asset.
The Group expenses repair and maintenance costs when they are incurred. Depreciation is recorded on the straight-line method based on
the estimated useful lives of the assets as follows:
Schedule of estimated useful lives of property, plant and equipment
Furniture, fixtures and equipment 5 or 7 years
Automobile 3, 5 or 7 years
Computer equipment, bitcoin server 3 years
Leasehold improvements The shorter of the estimated life or the lease term
PV solar system 20 or 25 years
(n) Intangible Assets other than Goodwill, net Intangible assets consist of customer
relationships, technology, patents and other. Amortization is recorded on the straight-line method based on the estimated useful lives
of the assets.
(o) Impairment of Long-lived Assets The Group’s long-lived assets
include property and equipment, project assets and other intangible assets with finite lives. The Group evaluates long-lived assets for
impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances
require a long-lived asset or asset group be tested for possible impairment, the Group first compare undiscounted cash flows expected
to be generated by that asset or asset group to its carrying amount. If the carrying amount of the long-lived asset or asset group is
not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying amount exceeds its fair
value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party
independent appraisals, as considered necessary. Any impairment write-downs would be treated as permanent reductions in the carrying amounts
of the assets and a charge to statement of operations would be recognized.
(p) Goodwill Goodwill represents the excess of the
purchase consideration over the fair value of the identifiable tangible and intangible assets acquired and liabilities assumed of the
acquired entity as a result of the Group’s acquisitions of interests in its subsidiaries. Goodwill is not amortized but is tested
for impairment on an annual basis, or more frequently if events or changes in circumstances indicate that it might be impaired. The Group
has an option to first assess qualitative factors to determine whether it is necessary to perform the quantitative goodwill impairment
test. In the qualitative assessment, the Group considers primary factors such as industry and market considerations, overall financial
performance of the reporting unit, and other specific information related to the operations. Based on the qualitative assessment, if it
is more likely than not that the fair value of each reporting unit is less than the carrying amount, the quantitative impairment test
is performed. In performing the quantitative impairment
test, the Group compares the fair values of each reporting unit to its carrying amount, including goodwill. If the fair value of each
reporting unit exceeds its carrying amount, goodwill is not considered to be impaired. If the carrying amount of a reporting unit exceeds
its fair value, the Group recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s
fair value; the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Application of a goodwill
impairment test requires significant management judgment, including the identification of reporting units, assigning assets, liabilities
and goodwill to reporting units, and determining the fair value of each reporting unit. The judgment in estimating the fair value of reporting
units includes estimating future cash flows, determining appropriate discount rates and making other assumptions. Changes in these estimates
and assumptions could materially affect the determination of fair value for each reporting unit.
(q) Income Taxes The Group accounts for income taxes
under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable
to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and
operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply
to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax
assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance
is recognized if it is more likely than not that some portion, or all, of a deferred tax asset will not be realized. The Group recognizes in the consolidated
financial statements the impact of a tax position, if that position is more likely than not of being sustained upon examination, based
on the technical merits of the position. In evaluating whether a tax position has met the more-likely-than-not recognition threshold,
management presumes that the position will be examined by the appropriate taxing authority that has full knowledge of all relevant information.
In addition, a tax position that meets the more-likely-than-not recognition threshold is measured to determine the amount of benefit to
be recognized in the financial statements. The tax position is measured at the largest amount of benefit that is greater than 50 percent
likely of being realized upon settlement. The Group’s tax liability associated with unrecognized tax benefits is adjusted periodically
due to changing circumstances, such as the progress of the tax audits, case law developments and new or emerging legislation. Such adjustments
are recognized entirely in the period in which they are identified. The Group records interest and penalties related to an uncertain tax
position, if and when required, as part of income tax expense in the consolidated statements of operations. No reserve for uncertainty
tax position was recorded by the Group for the years ended December 31, 2021, 2020 and 2019.
(r) Revenue Recognition The Group adopted Accounting Standards
Codification (“ASC”) No. 606, “Revenue from Contracts with Customers” (“ASC 606” or “Topic 606”).
The Group’s accounting practices under ASC Topic 606 are as followings: The Group generates revenue from sales
of PV components, roofing and solar energy systems installation, electricity revenue with Power Purchase Agreements (“PPAs”),
sales of PV project assets, sales of pre-development solar projects, sales and leasing of EVs and others for the years ended December
31, 2021, 2020 and 2019. Sale of PV components Revenue on sale of PV components is
recognized at a point in time following the transfer of control of such products to the customer, which typically occurs upon shipment
or acceptance of the customer depending on the terms of the underlying contracts. Revenue from roofing and solar energy systems installation
Revenue from roofing and solar energy system installation
is recognized over time . For revenue from solar energy system installation, the Company’s
principal performance obligation is to design and install a customize solar energy system, sometimes, reinstall the customer’s existing
solar energy system that is interconnected to the local power grid and for which permission to operate has been granted by a utility company
to the customer. For roofing the Company’s principal performance obligation is to design and build roof system per customer selection. All costs to obtain and fulfill contracts associated with
system sales and other product sales are expensed to cost of revenue when the corresponding revenue is recognized. The Company recognizes revenue using a cost-based input
method that recognizes revenue and gross profit as work is performed based on the relationship between actual costs incurred compared
to the total estimated cost of the contract. In applying cost-based input method, the Company uses the actual costs incurred to the total
estimated cost, to determine the Company’s progress towards contract completion and to calculate the corresponding amount of revenue
and gross profit to recognize. Electricity revenue with PPAs The Group sells energy generated by
PV solar power systems under PPAs. For energy sold under PPAs, the Group recognizes revenue each period based on the volume of energy
delivered to the customer (i.e., the PPAs off-taker) and the price stated in the PPAs. The Group has determined that none of the PPAs
contains a lease since (i) the purchaser does not have the rights to operate the PV solar power systems, (ii) the purchaser does not have
the rights to control physical access to the PV solar power systems, and (iii) the price that the purchaser pays is at a fixed price per
unit of output. Sale of PV project asset The Group’s sales arrangements
for PV projects do not contain any forms of continuing involvement that may affect the revenue or profit recognition of the transactions,
nor any variable considerations for energy performance guarantees, minimum electricity end subscription commitments. The Group therefore
determined its single performance obligation to the customer is the sale of a completed solar project. The Group recognizes revenue for
sales of solar projects at a point in time after the solar project has been grid connected and the customer obtains control of the solar
project. Sales of pre-development solar projects For sales of pre-development solar
projects in which the Group transfers 100% of the membership interest in solar projects to a customer, the Group recognizes all of the
revenue for the consideration received at a point in time when the membership interest was transferred to the customer, which typically
occurs when the Group delivered the membership interest assignment agreement to the customer. The contract arrangements may contain
provisions that can either increase or decrease the transaction price. These variable amounts generally are resolved upon achievement
of certain performance or upon occurrence of certain price reduction conditions. Variable consideration is estimated at each measurement
date at its most likely amount to the extent that it is probable that a significant reversal of cumulative revenue recognized will not
occur and true-ups are applied prospectively as such estimates change. Changes in estimates for sales of
pre-development solar projects occur for a variety of reasons, including but not limited to (i) EPC construction plan accelerations or
delays, (ii) product cost forecast changes, (iii) change orders, or (iv) occurrence of purchase price reduction conditions. The cumulative
effect of revisions to transaction prices are recorded in the period in which the revisions to estimates are identified and the amounts
can be reasonably estimated. Revenue from sales and leasing of EV The Group recognizes revenue from sales
of EV at a point in time following the transfer of control of such products to the customer, which typically occurs upon the delivery
to the customer for EV sales. The Group determined that the government grants related to sales of EV should be considered as part of the
transaction price because it is granted to the EV buyer and the buyer remains liable for such amount in the event the grants were not
received by the Group or returned due to the buyer violates the government grant terms and conditions. EV leasing revenue includes revenue
recognized under lease accounting guidance for direct leasing programs. The Group accounts for these leasing transactions as operating
leases under ASC 840 Leases, and revenues are recognized on a straight-line basis over the contractual term. Other revenue Other revenue mainly consist of revenue
generated from bitcoin mining and related equipment sales and hosting service, sales of component and charging stations, sale of Alfalfa
hay, engineering and maintenance service, shipping and delivery service and other. Revenue on bitcoin mining and
related equipment sales, alfalfa hays and component and charging stations were recognized at a point in time following the transfer of
control of such products to the customer, which typically occurs upon acceptance of the products made by the customer, and upon
delivery of the products to the hosting site or receipt place assigned by the customer, installed and set up the products for sale
of bitcoin mining equipment. Revenue for hosting service, engineering
and maintenance service and shipping and delivery service are recognized on a straight-line basis over the contractual term.is recognized
over time as services are performed and based on the output method related to the time incurred during the service period. There was no revenue generated from
bitcoin mining and related equipment sales and hosting service, or alfalfa hays sales during the years ended December 31, 2020 and 2021. Disaggregation of revenues The following table illustrates the
disaggregation of revenue by revenue stream and by timing of revenue recognition for the years ended December 31, 2021, 2020 and 2019:
Schedule of disaggregation of revenues
By revenue stream For the year ended December 31, 2021
Sales of PV components Revenue from roofing and solar systems installation Electricity revenue with PPAs Sales of pre-development solar projects Sales and leasing of EV Others Total
Australia $ 123,138 $ – $ – $ – $ – $ 1,110 $ 124,248
Japan – – – – – 65 65
Italy – – 690 – – – 690
United States – 29,028 – 894 2,336 835 33,093
United Kingdom – – 1,211 – – – 1,211
Greece – – 2,686 – – – 2,686
Total $ 123,138 $ 29,028 4,587 $ 894 $ 2,336 $ 2,010 $ 161,993
By revenue stream For the year ended December 31, 2020
Sales of PV components Electricity revenue with PPAs Sales of PV project asset Sales of pre-development solar projects Sales and leasing of EV Others Total
Australia $ 112,442 $ – $ – $ – $ – $ 1,062 $ 113,504
Japan – – 3,788 – – – 3,788
Italy – 615 – – – 41 656
United States – – 16,113 101 377 271 16,862
United Kingdom – 1,023 – – – – 1,023
Greece – 2,783 – – – 12 2,795
Total $ 112,442 $ 4,421 $ 19,901 $ 101 $ 377 $ 1,386 $ 138,628
By revenue stream For the year ended December 31, 2019
Sales of PV components Electricity revenue with PPAs Sales of PV project asset Sales of pre-development solar projects Others Total
Australia $ 79,470 $ – $ – $ – $ 1,048 $ 80,518
Japan – – 9,563 – – 9,563
Italy – 1,365 – – – 1,365
United States 1,471 – – (2,835 ) 5,684 4,320
United Kingdom – 979 – – – 979
Greece – 1,024 – – 114 1,138
Total $ 80,941 $ 3,368 $ 9,563 $ (2,835 ) $ 6,846 $ 97,883 Contract balance The following table provides information
about contract assets and contract liabilities from contracts with customers:
Schedule of accounts receivables and contract liabilities
December 31, 2021 December 31, 2020
Accounts receivable $ 22,599 $ 17,061
Contract assets $ 1,621 $ –
Advance from customers $ 4,924 $ 1,377 The contract assets primarily relate
to the Group’s rights to consideration for work completed but not billed at the reporting date, primarily for the revenue from roofing
and solar energy systems installation in the United States. The contract assets are transferred to receivables when the rights become
unconditional after billing is issued. Advance from customers, which representing
a contract liability, represents mostly unrecognized revenue amount received from customers. Advance from customers is recognized as (or
when) the Group performs under the contract. During the years ended December 31, 2021, 2020 and 2019, the Group recognized $ 1,377 17,161 8,159 (s) Warranties Workmanship Warranty for roofing
and solar energy systems installation For the revenue from roofing and solar
energy systems installation in the United States, the Group provides a workmanship warranty for 10 years to cover the quality of the Group’s
service. The warranty is designed to cover service defects and damages to customer properties caused by the Group’s installation
of the solar energy systems or roofing service. The 10-year warranty is consistent with the term provided by competitors and is provided
by the Group to remain market competitive. The Group determined that its 10-year workmanship warranty constitutes an assurance-type warranty
and should continue to be accounted for under ASC 460 - Guarantees, instead of a service-type warranty which should be accounted for under
Topic 606. Based on historical experience and projections of warranty claims, and estimated replacement costs, the Group currently provides
a reserve for the workmanship warranty based on 1% of sales of roofing and solar energy system installation, to be periodically adjusted
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