Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Details)

v2.4.1.9
Summary of Significant Accounting Policies (Details)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 3,261,360us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount 3,525,904us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Convertible Notes Principal [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 0us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConvertibleNotesPrincipalMember
2,650,858us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConvertibleNotesPrincipalMember
Convertible Notes Accrued Interest [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 0us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConvertibleNotesAccruedInterestMember
100,224us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConvertibleNotesAccruedInterestMember
Consulting Warrant [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 278,228us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
278,228us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_ConsultingWarrantMember
Financing Warrant [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 152,778us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
220,905us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_FinancingWarrantMember
IPO Warrants [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 460,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_InitialPublicOfferingWarrantMember
0us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_InitialPublicOfferingWarrantMember
IR Consulting Warrant [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 36,000us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_IrConsultingWarrantMember
0us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= watt_IrConsultingWarrantMember
Stock Option [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 1,607,075us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_StockOptionMember
275,689us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_StockOptionMember
Restricted Stock Units (RSUs) [Member]    
Summary Of Significant Accounting Policies [Line Items]    
Potentially dilutive securities 727,279us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_RestrictedStockUnitsRSUMember
0us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
/ us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis
= us-gaap_RestrictedStockUnitsRSUMember